The Vampire Diaries by L.J. Smith have seen a resurgence in popularity thanks to
Twilight, which I find amusing since I read them in middle school many years ago. I would recommend the original trilogy, "The Awakening", "The Struggle", and "The Fury". The first sequel, "Dark Reunion" was also good. I didn't think the most recent volume "The Return: Nightfall" was as good as the original books, but I'm not the target audience anymore so take that with a grain of salt.
If it's not vampires in particular that she's looking for, but just supernatural YA books with a bit of romance in them, another L.J. Smith trilogy called "The Secret Circle" may also appeal.
And finally, I would be remiss if I did not recommend "The Demon's Lexicon" by Sarah Rees Brennan. It does not have much in the way of romance but it's a very well-written supernatural story by a young woman who got her start writing fanfiction and became a published author.