Some kids really express themselves well in writing. They may enjoy writing their own book over the summer.
Let your child pick the subject or plan the story. It’s their book after all, although you can give advice. Depending on age, they can write it all out by hand or type it on the computer. Writing it out by hand is great practice for kids, especially those who need to improve their handwriting. Don’t forget the illustrations.
For kids too young to write, you can have them dictate the story to you. You won’t get free time for yourself this way, but your child will appreciate it.
Binding the book can be as simple as holes punched in each page and some yarn, or you can do a better job. You can even consider having your child write it in a journal so that it’s already bound.