Here are some books I suggest for your tweens (and some for their younger siblings):
The first book is DD’s favorite book. It’s an adventure story about a boy whose father leaves him a locked wooden box with the words, “The Meaning of Life” engraved on top and four locks on each side. He and a friend work together to search for the missing keys to reveal the contents and, perhaps, the meaning of life. Well worth your child’s time!!