Early years

Carreira began learning to skate in 2003.^[1] Her first coach was Yvan Desjardins.^[7] She competed with Simon-Pierre Malette-Paquette from 2006 until 2013. The duo won sectional titles from the juvenile level through novice. Representing Quebec, they became the 2012 national champions at the pre-novice level. They placed fifth in the novice ranks at the 2013 Canadian Championships.

2014–2015 season

In April 2014, Carreira teamed up with American ice dancer Anthony Ponomarenko. The two decided to represent the United States. It was Ponomarenko's mother, Marina Klimova, who thought the team would eventually be a good match after seeing Carreira in Lake Placid, NY.^[8] Their Junior Grand Prix (JGP) debut came in September 2014; they placed fifth in Ostrava, Czech Republic, and then fourth in Tallinn, Estonia. They finished fifth in the junior event at the 2015 U.S. Championships.^[9]

2015–2016 season

Competing in the 2015 JGP series, Carreira/Ponomarenko placed fourth in Riga, Latvia, and then won the silver medal in Toruń, Poland. They received the pewter medal for fourth place at the 2016 U.S. Championships.^[9]

2016–2017 season: Junior World bronze

Carreira/Ponomarenko won silver medals at both of their JGP events and finished fourth at the JGP Final, held in December in Marseille, France. In January, they took the silver medal at the 2017 U.S. Championships, having placed third in the short and second in the free.^[9] Ranked sixth in the short and third in the free, they won the bronze medal at the 2017 World Junior Championships, which took place in March in Taipei, Taiwan.^[8]

2017–2018 season: Junior World silver

Winning gold at both of their JGP assignments, in addition to the Lake Placid Ice Dance International, Carreira/Ponomarenko capped off 2017 with a second-place finish at the JGP Final, held in December in Nagoya, Japan. The following month they became the new US junior champions at the 2018 U.S. Figure Skating Championships. In March, they won silver at the 2018 World Junior Championships.^[9]

2018–2019 season: First Grand Prix medal

Pasquale Camerlengo joined their coaching team ahead of the 2018–2019 season.^[10] Making their senior international debut, Carreira/Ponomarenko achieved silver at the 2018 CS U.S. Classic in Salt Lake City, having finished second to Hubbell/Donohue. They won the bronze medal at the 2018 CS Nebelhorn Trophy. For their Grand Prix debut, Carreira/Ponomarenko finished fifth at the 2018 Grand Prix of Helsinki. At their second assignment, they won the bronze medal at the 2018 Rostelecom Cup.^[11] Following the conclusion of the Grand Prix, they won the gold medal at the 2018 CS Tallinn Trophy.^[9]

Carreira/Ponomarenko concluded their season at the 2019 U.S. Championships, where they placed fifth.^[12]

2019–2020 season

Beginning on the Challenger series, Carreira/Ponomarenko won silver for the second consecutive U.S. Classic and a second bronze medal at Nebelhorn Trophy. They won gold at their final Challenger event in November, the Asian Open Trophy, having finished first in both segments.^[9]

At their first Grand Prix, the 2019 Skate America, they placed sixth in the rhythm dance after errors on their twizzles. Carreira remarked it was "probably the worst time we have ever performed" the program.^[13] They remained in sixth place after the free dance, which Ponomarenko called "redeeming."^[14] At their second GP event, the 2019 NHK Trophy, they finished fifth in the rhythm dance, but a lift error in the free dance placed them in seventh in the free and sixth overall.^[15]

Carreira/Ponomarenko placed fourth in the rhythm dance at the 2020 U.S. Championships.^[16] Fourth in the free dance as well, they would have placed third in that segment but for the invalidation of their choreographic character step sequence due to a violation of the distance requirement. Taking the pewter medal, they stood on the senior national podium for the first time in their careers.^[17]

2020–2021 season: Coaching move

Carreira broke her foot during the spring quarantine period in response to the COVID-19 pandemic, though she had recovered by the time the rink reopened in the summer.^[18] With the pandemic affecting international travel, Carreira/Ponomarenko were assigned to compete at the 2020 Skate America, attended mainly by dance teams training in the United States.^[19] They won the bronze medal.^[20]

On January 10, it was announced that they had withdrawn from the 2021 U.S. Championships.^[21] Carreira confirmed it was a positive COVID test of a rink mate that caused their withdrawal.^[22]

On January 27, Carreira announced on Instagram that she and Ponomarenko would be departing their longtime coach Igor Shpilband.^[23] Two weeks later, U.S. Figure Skating announced that Carreira and Ponomarenko would be moving to train at the Ice Academy of Montreal's new Ontario campus in London, Ontario, coached by former Olympic champion Scott Moir.^[24]

2021–2022 season: Four Continents bronze

Carreira/Ponomarenko began their season at the 2021 CS Lombardia Trophy, where they placed fourth.^[25] They were eighth at the 2021 CS Finlandia Trophy.^[26]

On the Grand Prix, Carreira/Ponomarenko placed eighth at the 2021 Skate Canada International.^[27] They were fourth after the rhythm dance at the 2021 Internationaux de France, but dropped to fifth overall with a seventh-place free dance after an extended lift deduction.^[28]

At the 2022 U.S. Championships, Carreira/Ponomarenko were fifth in the rhythm dance but fell to seventh place after the free dance.^[29] They were named to the team for the Four Continents Championships in Tallinn later in January. Third in both segments, they won the bronze medal in their first appearance at a senior championship event. Carreira said they were "happy we're able to end our season with our best free dance, I think. So yes, we're overall really happy, and we want to continue growing into the next quad."^[30]

2022–2023 season

Following the conclusion of the 2021–22 season, Ponomarenko required ankle surgery, which delayed their preparations for the coming season. He revealed that he had been suffering ongoing ankle pain since "severely" spraining it in 2015 and developing joint damage. After years of skating through the pain, it had reached the point where "every opinion I heard was: 'Get the surgery.' Since the Olympic quad was over, this was the time to get the surgery done to make sure I'm fully ready for the next four years." While Ponomarenko spent three months recuperating in Colorado Springs, Carreira continued training by herself in London. When they resumed working together in May, retired ice dancers Madison Hubbell and Adrián Díaz joined their coaching team.^[31]

Foregoing the Challenger series to start the season, Carreira and Ponomarenko made their season debut on the Grand Prix at the 2022 MK John Wilson Trophy in Sheffield. They placed fourth in both segments and fourth overall, 11.53 points back of Canadian bronze medalists Lajoie/Lagha, their former junior rivals.^[32] At the 2022 Grand Prix of Espoo, Carreira/Ponomarenko were third in the rhythm dance, 1.14 points clear of home team Turkkila/Versluis, and described themselves as "really happy with the performances."^[33] In the free dance, they slipped to fourth in that segment and fourth overall, being overtaken by the Finns for the bronze medal.^[34][35]

Following the Grand Prix, Carreira/Ponomarenko made a belated Challenger appearance, winning gold at the 2022 CS Golden Spin of Zagreb.^[36] With presumptive national silver medalists Hawayek/Baker sitting out the 2023 U.S. Championships for health reasons, the national podium was more open than would otherwise have been the case. Considered likely bronze medalists going in, Carreira/Ponomarenko unexpectedly placed fourth in the rhythm dance due to a twizzle error.^[37] In the free dance they overtook new team Zingas/Kolesnik for the bronze medal.^[38]

As national bronze medalists, they were named to the 2023 Four Continents Championship team, and also as first alternates for the 2023 World Championships, the third berth there having been given to Hawayek/Baker.^[39] They placed fourth in the rhythm dance at Four Continents, 2.07 points back of third-place Lajoie/Lagha.^[40] Fifth in the free dance, they remained in fourth place, beating domestic rivals Green/Parsons.^[41]

On February 24, it was announced that Hawayek/Baker had withdrawn from the World Championships due to continued health problems. As first alternates, Carreira/Ponomarenko were called up to make their Worlds debut.^[42] They finished tenth.^[9]

2023–2024 season: National silver and Four Continents bronze

For the first time since the onset of the pandemic, Carreira and Ponomarenko had the entire offseason for training and other upgrades, which in this case included new equipment, nutritional plans, and athletic trainers.^[43] Starting the season at the 2023 CS Nebelhorn Trophy, Carreira/Ponomarenko came fourth, before winning the silver medal at the 2023 CS Finlandia Trophy.^[9] On the Grand Prix, they came fourth at the 2023 Grand Prix de France. Carreira said that despite some technical errors, "we put out two solid performances this weekend that we are proud of."^[44] They followed this with a fourth-place finish at the 2023 Grand Prix of Espoo.^[45]

In advance of the 2024 U.S. Championships, Carreira/Ponomarenko were preemptively named to the American team for the 2024 Four Continents Championships in Shanghai, which was to take place the following weekend.^[46] At the national championships, the team finished second in the rhythm dance segment, before winning the free dance segment over a flu-stricken Chock/Bates; the latter remained in first place overall on the strength of their rhythm dance lead, and Carreira/Ponomarenko claimed the national silver medal for the first time.^[47] At the Four Continents Championships, they finished third in the rhythm dance. They were only fifth in the free dance after a twizzle error from Carreira, but remained third overall, 1.07 points clear of fellow American team Zingas/Kolesnik in fourth. Claiming their second championship bronze, Ponomarenko noted that they team had experienced much in the two years since their first, including "lows" relating to his ankle surgery, so "being back here and having these two years of growth with Christina and the rest of our coaching team, it's a big significant moment."^[48]

At the 2024 World Championships in Montreal, Carreira/Ponomarenko finished a new high seventh overall with a total score of 200.32 points. Carreira said that hitting the 200-point mark had been a goal for the team "for a couple of years and it's of course great to have reached that."^[49]

Ice dance with Anthony Ponomarenko

Ice dance with Anthony Ponomarenko