The one indication that she's consciously trying to be a heroine is that she's learning all those quotes. And that section comes right after the narrator saying about becoming a heroine.

I'm personally conflicted about whether or not she's trying to do it - or if the narrator's just mocking the growing up process. We know that she has read a lot of novels - it says right before the quote section that novels are about the only type of reading that she enjoys until she turns 15. And I can see her casting herself in the role of the heroine (except, of course, the very discouraging accident of her birth which gave her living and normal parents!;).