Is your mother a good independent learner? Or does she need to be instructed in a classroom-style setting?
If your mother is a decent independent scholar, she would probably benefit from having the NCLEX-PN review books that were authored by Linda Anne Silvestri. I know of people who failed the NCLEX-PN on the first attempt and then proceeded to read the entire Silvestri book anywhere from one to three times. Guess what? They passed on the second try. The Silvestri book can be found at any local Borders book store or Barnes and Noble if not online at Amazon.
If your mom prefers a classroom review, then doesn't her school offer review classes to the graduates? My school offered a free four-day NCLEX review to all graduates, but I declined the invitation.