@daallday I think there's a part of her heart that is very attached to the adult version of him who appears later in the novel; that is the version of him I believe she will have some sort of romance with.
But yeah, to me the mental age is super relevant. I am an adult. Even if my body changes I am still me with my adult maturity, experiences and personality. So I will still be attracted to adults and I will still see kids as people who I should nurture and protect. To me, seeing an adult in a teenage body pursue a child is in the same category as the adults who pretend to be teenagers online.