Mandie and the Secret Tunnel (first book in the Mandie series)
by Lois Gladys Leppard
This is the first in a series of "Mandie books." I think I would have liked these books as a girl, and I'm sure my daughter will enjoy them. (There are twenty-something in the series.) The writing isn't fantastic, but it's adequate and there are no glaring errors. However, the story is quite compelling, which is what makes it worth reading (part adventure/mystery, part heart-warming family story). If the rest of the series follows suit there will be much to like. The book contains nothing offensive.
Age recommendation: 9 - 12 years old (writing level is a bit younger, but it's OK)