Lily has a couple defining characteristics:

1) 'In Tents Debate' reveals that she's already one of the more 'Girly' of the sisters, and that she likes the beach.

2) She seems to enjoy dressing up like/ imitating animals (She's done so for a bear, a shark, a squirrel, a cat, a kangaroo joey, and probably one or two others I can't remember), perhaps she could grow to develop an interest in acting/ theatre?

3) She's surprisingly good at finger- painting for her age (i.e. in 'L is for Love,' the finger- painting she gives to her teddy bear is pretty detailed for a 1- year- old), so maybe she could develop an interest in art?