I sell children's books for a living, and read almost nothing but. The first does not necessarily cause the second, as books for children and teens are better than anything in the world.
When I read adult books, I usually read fluff. I freely admit this. And as fluff goes, this one's pretty good. It's set in England, which always seems to lend fluff an extra but of legitimacy. But I stand up for the right of people to read what they want, and what I often want is a nice piece of chick lit with a strong main character and a happy ending.