I had largely forgotten about Burningham's books, but remember reading an awful lot of them during my childhood! Fun and delightful.

A 1001 CBYMRBYGU. A mom, a dad, and their daughter, Shirley, go to the beach. On one side of the page, the mom and dad sit in their beach chairs, talking about the various dangers of the beach. On the other side, a silent Shirley, apparently unbeknownst to them, goes off on a pirate ship and finds treasure.

(Picture of mom and dad sitting in beach chairs on the left)
“Why don’t you go and play
with those children?”
(Picture of Shirley rowing a boat out to a large pirate boat is on the right)