There is a little boy in our mothers group who is very similar- just really quite happy to hang out on his back or tummy. He started crawling much later than any of the other kids- I would say not until 10.5-11 months. But when it did happen, it happened quite quickly. He's now almost 12 months and will, but he's still really quite happy to sit or lie or roll a bit. All the other kids are like bumper cars with each other and he's just happy chilling. He is perfectly normal as far as development, its just the personality. I'm sure your DD is the same, I wouldn't worry. They have to have some motivation to do all that hard crawling work and if your DD is happy to be where she is, why would she bother trying to move? She will get there in her own time. I wouldn't worry until 12 months, but I've no medical basis for that- just my instinct! I'm sure your MCHN has some guidelines?