After playing for Safa Claror, Txell Alarcón joined Femení Sant Adrià in 2014 and she remained in the club during 6 years becoming U12 Catalan Finalist 14/15, U13 Catalan Finalist 15/16, U14 Catalan Champion 16/17, U14 Spanish Finalist 16/17, U16 Catalan and Spanish Champion 17/18 and U16 Catalan and Spanish Finalist 18/19.

Txell was also a member of the Catalan regional team that became U14 Spanish Finalist in 2017 and U16 Spanish Finalist in 2019 and she was also a member of the Spanish National Team that won the Gold Medal in the Friendship Tournament played in Nice in 2015 and impressed in the U16 European Championship played in 2019 averaging 8.9 points and 4.7 rebounds in 21 minutes per game with Spain.

In the 2019/20 season and still at 16 years old, Txell Alarcón was also one of the main players of the Femení Sant Adrià senior team that qualified first in their Liga Femenina 2 group, averaging 6.8 points, 3.6 rebounds and +7.8 efficiency in 23 minutes per game.

In the 2020/21 season and still as an U18 player, Txell Alarcón joined Campus Promete in Spanish top division and she averaged 5.1 points and + 5.3 efficiency in 15 minutes per game (13.6 points +14.1 efficiency per 40 minutes), shining already in her first official game in the competition with 17 points in 17 minutes and being the best 3 point scorer in the competition, scoring 56.4% of her 3 point shots.

In the 2021/22 season, Txell Alarcón stayed with Campus Promete and averaged 4.8 points in 20 minutes per game.

In the 2022 summer, Txell Alarcón won the Gold Medal with the Spanish national team in the U20 European Championship and she was the final´s top scorer with 16 points in addition with being the tournament´s second best 3 point shooter with 46.2% from deep.

Later on, in the 2022/23 season, Txell Alarcón signed with Araski and had a very good season averaging 7.8 points in 24 minutes per game with 35% from the 3 point line.

In April 2023, Txell Alarcón was selected with the 32nd pick by the Washington Mystics in the WNBA Draft.

Txell Alarcón averaged 9 points, 3.4 rebounds and +9.4 efficiency in 21 minutes per game and won the Bronze Medal in the U20 European Championship with the Spanish national team.

Txell re-signed with Araski during the 2023/24 season and averaged 6.1 points and +7 efficiency in 20 minutes per game with 39.1% in three pointers.