In Dr. Blum's case, that statement is true.
On recommendations on sex books for kids:
"As for book, I have been out of this for a while but when my kids were little I always had Peter Mayle's books lying around so that they could pick them up. look at them and when they were older start to read them"
A look at Mayle's book:
"Where Did I Come from?" by Peter Mayle
Reading level: Ages 4-8
"this funny, down-to-earth sex - education classic describes the mechanics of reproduction in an appealing manner that young children will really connect with. Filled with cartoon-like drawings and matter-of-fact descriptions of everything from what sex feels like ( in child-friendly terms ) to how a baby is actually born, this picture book will be most helpful to parents when they're having The Talk."