The dog is displaying dominace over the child. You didn't mention how old the child is but I would guess under a year if she is crawling. You must correct the dog when doing this by putting it in a time out in a sit or down position immediately when this is done. You can't wait even 10 seconds or the dog won't know the reason for the time out. Keep the dog in the sit or down for about 3 minutes, increasing the time by a minute if the behavior continues. Be consistent every time it happens.

If you don't get this under control now, when the child gets older and is walking, you could have a potential major problem on your hands.