Magic by the Lake! And then The Time Garden! And THEN Seven-Day Magic, and then you can skip the Well-Wishers books because the kids never figure out if it really is magic and I HATED that as a kid. Oh, and The Enchanted Castle (Nesbit) is a great one to read after you've finished the Eager books, because he references it in Half Magic. And while you're on a Nesbit kick, you've got the three Five Children and It books (Phoenix and the Carpet is my favorite), and Wet Magic (which I adore, even if parts of it make me grind my teeth nowadays, but all Nesbit's books do that), and The Book of Dragons, which is a collection of short stories and so maybe easier to read than her chapter books.

*deep breath* I love Edward Eager, is what I'm saying here. And I've got to read Half Magic to MY kids this winter now.

(I realize you probably know all these books without me rattling them off, since you are both a librarian and a lifelong reader, BUT I have to share anyway. Because yay, books.)