She played for the youth national team at every age level, captaining the United States to bronze at the 2024 FIFA U-20 Women's World Cup, after which she was named U.S. Soccer Young Female Player of the Year.

[6][7] She joined Hingham club South Shore Select at age six and later trained at times with the Boston Bolts boys' team.

[14] In her redshirt freshman season, she won the Atlantic Coast Conference regular-season title and ended the year with ten goals, the second most on the team.

[21] She scored her first professional goal on March 22, shooting from the corner of the penalty box off a long dribble in a 2–1 home win over the North Carolina Courage.

[22] She was deployed as a winger at the start of the season, scoring or assisting on five of her team's first seven goals, before moving to a more playmaking role as an attacking midfielder at the end of June.

She scored four goals during the tournament, helping the United States finish runners-up to Mexico and qualify for the 2024 FIFA U-20 Women's World Cup.

[8][33] Wearing the captain's armband, Sentnor led the United States to third place at the U-20 Women's World Cup, the country's best result since 2012.

[37] After falling to eventual champions North Korea in the semifinals, Sentnor opened scoring in the third-place match, a 2–1 victory over the Netherlands.

[39] Head coach Emma Hayes gave Sentnor her first senior national team call-up on November 18, 2024, ahead of international friendlies against England and the Netherlands.