[3] Born in Rotherhithe / Bermondsey, Flaherty grew up in the London Borough of Southwark, located directly south of the River Thames.

[4] In September 2007, Flaherty joined the Arsenal Ladies Academy, which combines academic studies with football coaching.

Flaherty worked her way through the club, coming off the bench to make her senior debut in October 2006 against Birmingham City, in a Premier League Cup match, when only 15 years old.

[6][7][8] She was part of the Arsenal squad that made history by being the first team outside Germany or Scandinavia to win the UEFA Women's Cup.

"[14] Flaherty's first season with the team ended in disappointment, as they lost the league title to Liverpool on the final day of the campaign.

2015 proved much more successful, yielding the club's first ever major trophy – won at Wembley Stadium in the 2015 FA Women's Cup final.

[18] On 12 January 2023, Flaherty announced her retirement from football citing family reasons, following the passing of her father in late 2022.

[23] Flaherty was allotted 191 when the FA announced their legacy numbers scheme to honour the 50th anniversary of England’s inaugural international.

[30] Flaherty took part in a white-collar boxing match in August 2013, to raise money for Millwall's Girls' Centre of Excellence.