I'm getting quite upset that my 15 mth old is not walking, she sat at 6mths and crawled at 9mths. She can cruise and walk with her walker but she won't walk with her hand held, doesn't want to stand independently and prefers to knee shuffle. All her friends, even some who are 2 mths younger, are walking. I just feel like she is getting left behind and wondering what to do? Anyone in a similar position or with advice?