Yeah, I think it's important to remember that she's still pretty young. I don't remember if they gave an exact age, but I got the impression that she's somewhere between 18-21. We may technically adults at that age, but that doesn't mean we're mature. She's also been thrust into a brand new situation, and not at all in the manner she thought it would be.
I would say, yeah, she's probably a bit childish, but that's right for the character.