Early career Stapleton is from
Ballyfermot, and began playing soccer for
Cherry Orchard when she was eight years old. When she was 11 she became the first girl to be selected for the representative team of the Dublin and District Schoolboys League (DDSL). In 2020 Stapleton played for
Shamrock Rovers in the
Women's Under-17 National League. After Stapleton
captained Rovers to their 2–0 League final defeat by
Cork City, she spoke out against
sexist remarks made by
internet trolls on the comment section of the live feed.
Shelbourne Stapleton joined
Women's National League club
Shelbourne for the
2021 season, She enjoyed good form in her debut season at senior level, featuring in defence and
midfield for
Noel King's Shelbourne. Stapleton
sometimes played in attack, helping King plug gaps in the Shelbourne team caused by injuries and the departure of several players to professional clubs in the
United Kingdom. She was named WNL Player of the Month for October 2021, nominated for Young Player of the Year and named in the Team of the Season. Shelbourne overhauled
Peamount United on a dramatic final day to win the 2021 Women's National League title. Stapleton also played in the
2021 FAI Women's Cup Final, but Shelbourne were beaten 3–1 by
Wexford Youths. In
2022 Stapleton continued to play well as Shelbourne claimed a League and Cup "
double". She was named Young Player of the Year and retained her place in the Team of the Season. In the
2022 FAI Women's Cup Final Stapleton scored the opening goal and was
Player of the Match as Shelbourne beat
Athlone Town 2–0 to avenge their defeat in the previous year's final. In November 2022 she was reported to have made an agreement to join
West Ham United in June 2023, in preference to several other interested clubs.
West Ham On 28 July 2023, Stapleton was announced at West Ham. She made her league debut against
Leicester City on 17 December 2023.
Reading (loan) On 26 January 2024,
Reading announced the signing of Stapleton on loan from
West Ham United for the remainder of the season.She helped the club avoid relegation from the
Championship by scoring in a 1-0 victory against
Durham on 21 April 2024
Sunderland (loan) On 1 August 2024, Stapleton was announced at Sunderland. ==International career==