I remember that book! There were twins, and another brother a little older, and they had a treasure map on an island?

Yes! I think one was a cousin. And there was some story about how a great-grandparent had gone off to war (the Civil War!) and left a note/treasure map for his kids, and the great-grandmom washed it, so no one ever found the treasures....

What's interesting is there was a sequel, which I didn't know about until maybe college or later. My dad could've just given me that! :)

I always liked the Richard Peck books. There were two books that involved ghosts; the second one had a girl who was a medium seeing the dead from the Titanic, IIRC. I'll have to look that one up for its title--it was really excellent!

Sideways Stories from Wayside School. The Great Brain. Matilda. Anastasia Krupnik. Nate the Great. No Flying in the House. Mrs. Frisby and the Rats of NIMH. I guess she's still a little young for From the Mixed-Up Files of Mrs. Basil E. Frankweiler.

Oh, that's Ghosts I Have Been, I think, Kathy! I loved that. Richard Peck and John Neufeld were huge staples for me.

I'm bookmarking all of these because they're awesome.

Harriet the Spy Where the Sidewalk Ends Nancy Drew(although I might have been a little older for those...)

Is she too young for Edward Eager, Sox? Because I really enjoyed them, and I think if she likes Narnia, she'll like those, too.

Ghosts I Have Been

Yes! Such a good book. It was spun off from The Ghost Belonged to Me, which is also excellent.

Elizabeth Enright! Gone-Away Lake! The Melanies! The Four Story Mistake!

Though I'm not sure of the proper age group on those.

Ooh, I loved Elizabeth Enright, though got a bit confused over some of the old-fashioned terminology. Also loved Edward Eager. And E Nesbit!!

(Hi, we're buffistas. We could recommend books ALL DAY LONG)