Kelly, 25, was the youngest of seven siblings and grew up in Ealing, west London, spending her days playing in cages – enclosed park areas designed for sports – in her estate.
Having begun her career at Arsenal, she moved north to Everton, initially on loan, in 2016, when she was 18.
By the time Willie Kirk arrived at the club as manager in 2018, Kelly had already impressed but was known for her feisty character and a relentless competitive streak.
“She was really young and raw. I had heard some stuff about her attitude and things like that but I never, ever had that version of her,” Kirk told BBC Sport.
“I gave her a bit of freedom and told her to go and play and I think she responded to that. She was fiery at times but I never wanted to take that out of her as it’s made her the player she is today.
“She trained exactly the way she played. She wanted the ball all the time and hated giving it away. She had bags of energy so it was exciting to try and get her in the team.
“Maybe people forgot she was a young kid who moved up from London. Any fiery moments in training I almost encouraged because it wasn’t causing a problem.”
A major setback came with an ACL injury that forced her to miss the Olympic Games in 2021. She says it caused her to grow up a lot.
“I’ve stayed true to myself in terms of my personality. Maybe I was a little bit cheeky when I was younger. I remember [ex-Everton manager] Andy Spence getting at me sometimes,” she said.
“I feel like I’m just me, though. That maturity is when you grow older and you realise you can use people to help you improve and you can ask questions.
“I matured the most when I was injured. Everything gets taken away so quickly so now I think ‘why would you complain about such little things?’ You appreciate things so much more.”