The book I am looking for is a young adult book. I read it when I was a pre-teen in the early 90’s. It had twins, a boy and a girl, and the girl was named Willa. The boy may have been named August. They were also pre-teens. Their mother may have had a baby—a boy?? I remember trees, summer time and perhaps a tree swing or hammock. Maybe lemonade?
Try this one: Unclaimed Treasures, by Patricia MacLachlan.
https://www.goodreads.com/book/show/121454.Unclaimed_Treasures
YES!! This is it. Thank you. How did you do that?
“Willa’s twin brother” brought up a match on Google Books.
Huh, I didn’t know about google books. Thanks!
It’s one of the Google options like Images and News. Some books and periodicals come up themselves, but other times (like this) you find an old mention of it in a book review column or a book about other books, and that gives you enough information to find other mentions or listings on Amazon, abebooks, Worldcat, etc.