I am a big fan of sweet valley. This includes all series under the title Sweet Valley. I have almost read the whole collection and I am close to owning 400 of the 600 swet valley books written.
If you have a question let me know....I can tell you anything you want to know.
I find that some sweet valley books are very rare and har dto find. The Elizabeth series is especially the hardest. For this series you may have to include other countires in your search or you can try amazon.com as they have these books.