Ramona is forming strict ideas about what is for boys and what is for girls along quite arbitrary lines and without being wholly sure about different genders to begin with. Ramona was wearing her daddy’s hiking boots and when Juno tried to grab the laces Ramona announced that she mustn’t because “You are a boy! And these boots are for girls!” (Juno isn’t and they aren’t.)
These conversations are okay, of course. Ramona is simply processing the idea of gender its meaning and the language we use around it all. I don’t have (many) worries about her forever believing that forks are only ever to be used by womankind.