For Christmas get her Mists of Avalon by Bradley. It is a feminist retelling of the Arthurian legend and while it has its own issues, it is still a better female role model than Twilight.

Other recommendations: Anything Margaret Atwood (especially Cat's Eye or Handmaiden's Tale), Like Water for Chocolate by Laura Esquival, A Yellow Raft in Blue Water by Michael Dorris (such a good strong female characters book that I keep forgetting it is written by a man).

I thrived on teenage angst, that's an unavoidable stage. Most of us survive it, the unlucky do not (Romeo and Juliet as you recall were teenagers). And yes that codependency/first love/first crazy crush are part of that. Going through it gives you emotional maturity (hopefully as an adult).

However, throughout my teenage years my parents and librarians fed me a steady stream of books like those mentioned above (all of which I read as a teenager and re-read at least once as an adult) that when I was ready to shuck off teenage angst gave me a solid psychological footing to be an independent woman.