Early career Coombs began playing football aged seven or eight, when she joined a team run by her best friend's father. She progressed to
Arsenal's youth academy and began playing in the first team at 16. In September 2009, Coombs made her
UEFA Champions League debut in Arsenal's 9–0 win over
PAOK Thessaloniki. In summer 2011, Coombs played for American
W-League team
Los Angeles Strikers, scoring one goal in eight appearances.
Chelsea During the mid-season break of the inaugural
2011 FA WSL season, Coombs
transferred to
Chelsea. The club reached the
FA Women's Cup final for the first time in
2012, but were eventually beaten by
Birmingham City in a
penalty shootout after twice taking the lead in a 2–2 draw. In the 2013 mid-season break, Coombs had another stint with LA Strikers. In 2015 Chelsea won their first ever major trophy, in the
2015 FA Women's Cup Final at
Wembley Stadium. They then beat
Sunderland 4–0 in October 2015 to secure the
FA WSL title and a League and Cup
double. Teammates noted an improvement in Coombs' strength and power that season, a result of the team's transition from part-time to full-time training. During 2017 she eventually signed a two-year deal at Liverpool.
Manchester City In June 2019, after three years at Liverpool, Coombs signed for
Manchester City on a two-year contract, being part of the squad that won the
2020 FA Cup in her first season. Though she had not expected "to get straight in the team", Coombs later expressed disappointment at how little she had played for the club in her first season with them, remarking that she is a confidence player. She felt that time away from Man City due to the
COVID-19 pandemic after her difficult first season helped her come back better for the team. Coombs' second season at Manchester City was marked by a midfield featuring prominent American and British internationals, with Coombs pleased to be able to work with and be challenged by them in training, as it made her raise her level. In the 2021–22 season, City won the
2022 League Cup. and had a strong start to the season. During this time, she was a constant in a midfield that gradually incorporated different new signings. While other adaptations were made, Coombs retained her typical role. On 4 August 2025, it was announced that Coombs had signed a one-year contract extension with Manchester City, with the club praising her influence and popularity off the pitch as well as on it. On 30 April 2026, Coombs announced that she would retire from football at the end of the season. ==International career==