Flint earned international caps for England from Under-19s to Under-23s level, representing her nation at the 2013 UEFA Women’s U19 Championship, when England reached the final and the FIFA Women's U20 World Cup a year later.
After time at Manchester United’s Centre of Excellence, Flint then moved to Manchester City’s Academy in 2013 and the following year was called up to the senior side, signing her first contract at the age of 17, ahead of the club's first WSL campaign.
In July 2014, her goal against Chelsea was a 2014 FA WSL Goal of the Season contender, and in October, she was in the starting line-up when City won the 2014 FA Women’s Continental Tyres League Cup.
The forward signed for Preston North End Ladies, now Fylde Women, in the third tier in October 2015, returning in June 2016 after a short stint back in the WSL with Notts County Ladies.
In January 2017, she was recruited by Sheffield FC in WSL 2, before re-joining Fylde for a third spell in July 2017.
Flint moved to FA Women's National League side Blackburn Rovers Ladies in December 2017. She helped the Club to promotion into the FA Women’s Championship for the first time at the end of 2018/19 and by the end of her spell in Lancashire, had scored 70 goals in 66 games across three seasons.
Strong enough to win or protect possession and a fearsome attacking threat, Flint was in explosive form throughout her debut Foxes season in 2020/21 - top scoring with 21 goals and 17 of those in the FA Women's Championship.
After scoring twice on debut against her former side Blackburn, one of which was later named as 2020/21 Goal of the Season at the Club’s End of Season Awards, Flint found the net in all three league victories during December, winning the FA Women's Championship Player of the Month award.
She fired the Foxes to the second-tier title, scoring both goals in the win over Coventry United on 28 March, 2021, before netting the second goal against London City Lionesses that clinched promotion to the Barclays FA Women's Super League.
The forward was voted as Supporters’ Player of the Season and in May 2021, scored the winning goal in a 3-2 away victory over WSL side Manchester United in the fifth round of the Vitality Women’s FA Cup, ahead of signing a contract extension at the Club.
Another strike against the Red Devils would follow in the 2021/22 Continental Tyres League Cup, while Flint also netted the team's first-ever WSL goal, away at Aston Villa on 4 September, 2021.