J.K.
My daughter will be 12 months in two weeks and she JUST started to army crawl. However, she doesn't walk, she doesn't use stationary objects to lift herself up, and she doesn't get from lying to sitting. Her pediatrician gave her a referral to be evaluated by a physical therapist. The PT after seeing my daughter concluded that her abdominal muscles were weak and recommended PT for a few months, 1-2 times per week to help develop those muscles. I know it's hard, but I think you should definitely see those specialists and see what they have to say before you start worrying. At least if there's something wrong, it will be caught early and they can be dealt with ASAP.