The youngest of them, the strongest of them, and the only one still glad to be there.
Molly Hayes Hernandez is the youngest member of the Runaways and is characterised by her positive attitude. Allegra Acosta plays her, and Molly discovers she has superhuman strength.
The group needs her for a structural reason. Five teenagers arguing about whether their parents are evil is a good scene once; a child who wants to know whether they are still going to have dinner is what stops it becoming only that.