I would personally recommend Margot Adler's Drawing Down The Moon (second or third edition) and Starhawk's The Spiral Dance (again, later editions). If you won't mind, may I give your e-mail address to my Wicca & Neopaganism instructor? She can recommend VOLUMES of books and web sites that are pagan-friendly from the "testing the waters" to the "enjoys reading torturous doctoral dissertations just for fun" ;)
Has your sister logged onto The Witches' Voice? The address for their site is http://www.witchvox.com (for anyone interested). It's one web site that I've personally found to be quite informative.
I'll be watching the postings for any questions (and Gia's answer).
Bud blagosloven (blessed be in Russian/Ukrainian) Phyllis (aka Sidhe Uaine or Gaia Euphoria)