my daughter just turned 9 months last week, and she's not quite yet crawling yet. she's super long and lean (wearing 12-18 month clothes) and it took her a while before she was able to sit up on her own because she would just tip over. she has been developing fine and her doctor hasn't been concerned about anything. it just seems like everyone else's babies are crawling like crazy and even starting to walk, and my SIL made me feel like i was doing something wrong. anyone else going through the same thing at all?