I think the sexualization was deliberate in Push, though. That character was supposed to be acting creepily old for her years, and there was supposed to be a dissonance between age and behavior/looks. I think it was supposed to make us feel uncomfortable, and supposed to hint at how damaged she was, how not like a normal childhood she'd had.
That's how it read to me, anyway. It's one thing where a young teenager dressing and acting "sexy" is supposed to feel wrong, as I think it was meant to there. It's quite another thing when it's just presented as normal, the way normal thirteen year olds are supposed to dress and behave.