The 19-year-old forward, a graduate of the club’s Academy and Centre of Excellence, made her debut in 2016 and has gone on to make 38 appearances for the Reds, scoring three goals.
Charles was part of the England squad that secured bronze medals at the U20 World Cup last summer, having previously taken part in the U17 World Cup in 2016.
Her impressive form also saw her voted 'Rising Star' at the 2018 North West Football Awards.
Wirral-born Charles spoke of her delight at continuing her career with Vicky Jepson’s LFC Women squad.
Charles said: “I’ve grown up here, I love this club and I support this club, so I’m delighted to sign again.