Character Analysis
This blonde girl is in Zoey's Vampyre Sociology class, and she correctly answers one of Nefret's questions about the Amazons. This leads to Zoey thinking of her as "Ms. Perfect Student Elizabeth" (12.66)—but then Elizabeth introduces herself to Zoey in Drama class, saying that she has "no last name" (12.68). Which is odd, until she offers the following explanation to Zoey: "My last name was Titsworth. Can you imagine?" (12.70). We can imagine, and it ain't pretty.
Understandably, then, when Elizabeth learned upon her arrival to school that as a vampyre she could have a new name, she decided to ditch her birth name. She didn't want to choose a new name, though, hence the no last name bit.
Unfortunately, Stevie Rae brings Zoey the news that Elizabeth has died in one of her classes. Her body rejected the Change, and she just died—nothing could be done.
… except that's not the last we see of Elizabeth. When Zoey's sitting on top of the wall of the school, she sees Elizabeth: "When she saw me her eyes, which were a weird, glowing red, widened and then she made an odd shrieking sound before whirling around and disappearing with inhuman speed into the night" (17.21). Creepy. Zoey has no idea what this means, though, or whether she actually saw a ghost or what, so we're in the dark, too. For the time being, anyway.