Yes. You decide what goes in your book.
Before your book is created: on the "Review [Name]'s photos" screen, tap any photo to uncheck it and leave it out
To change the number of pages: on the "What's your budget?" screen, tap a price at the top. Lower prices collage more photos together for fewer pages. All your photos stay in your book
After your book is created: tap the "+" to add more photos. The picker opens with the same child and dates filtered, and you can clear either filter to see all your photos
To edit a collage in your Kid Yearbook:
Tap the collage page, then tap "Edit Collage"
To take a photo out of a collage, turn the photos back into individual pages, then remove the photo you don't want
To crop a photo or swap it for a different one, tap the photo
To move a photo to a different spot in the layout, tap and hold it, then drag it
When everything looks right, tap "Done"
Good to know: if only a few photos were found and you choose a higher price for a bigger book, burst photos (similar shots taken in a row) may be added to fill the extra pages.