I leave Pie to play alone when she's happy to (well I stay nearby but YKWIM). I think it's good for them to be able to play alone, you know?

wysiwyg, I doubt that CJ's crawling has much to do with playtime. I really think it's down to the individual bub. If anything playtime on the floor with you will help him develop those skills. Pie loves to climb on me

And SS, lol at the books - Pie has discovered she can crawl to all kinds of shelves & pull everything out. Then she leaves it & moves along to the next shelf but I let her go, cause it keeps her off the stairs....