You can copy photos from one Chatbook to another in the Chatbooks app or on Chatbooks.com, so you don't have to upload them twice.
Good to know:
Copying photos is also how you merge photos from two books into one.
Want to move photos within the same book instead? See How do I rearrange pages in a Monthbook, Monthly Mini, or Baby's First Year?
Looking to merge two Chatbooks accounts? See the merge section in How do I log in or fix login problems?
How do I copy photos to another book in the app?
Sign in to your account in the Chatbooks app.
From the Home page, tap the book you'd like to copy photos from.
Tap and hold a photo.
Tap any other photos you want to copy.
Tap the copy button (two squares) at the bottom of the screen.
Select the book you'd like to add the photos to.
How do I copy photos to another book on the web?
Log in to Chatbooks.com.
Click "Home" at the top of the page, or click "Account" and then "My Books."
Click the book you'd like to copy photos from.
Click "Rearrange pages" at the top right.
Click the photos you want to copy.
Click the copy button (two squares) at the bottom of the page.
Follow the on-screen instructions. Your photos will be added to the book you chose.