Ya know I have to wonder where Cass fits in this whole thing.
She lived in isolation till she was 8, and then she was pretty much a mute runaway till she was 15. (how she got from some island in South Asia to Gotham City I don't know...)
I guess, girl's an alien in comparison. Wait...there ya go. Perhaps she's like the poorest of illegal immigrants, hiding from mainstream society until she met Babs. Then she was isolated again, until she learned to talk.
It always seemed to me (especially when she interacted with others her age) that she was like the stereotype of the quiet Chinese exchange student. Super studious, smart, but socially unavailable/awkward/different. A real foreigner...