"Cute" is sort of broad, so it really depends on your character's other defining traits, I'd say. Like, is she more outgoing or is she the shy/awkward cute type? Does she have cute clumsy moments? Is she cute because she's always optimistic and cheerful or is she more the sort that struggles with insecurity and brings out protective instincts?

I guess what I really mean is, it might be good to go through her canon and look at the specific moments that make her seem cute, either to yourself or to the characters around her. Then from there you can consider how to mimic those cute moments in a game.