I would be very worried about leaving your dog around her AT ALL. If pits are not associated with children at a young age they can be dangerous. I chose to adopt a 6 month old pit that was raised around children, horses, cats, dogs, etc… and she just adores my 22 month old daughter. Like any dog that growls at children or even lunges at them I would be cautious, if it was me I’d have a hard time keeping the dog because I worry about my children’s safety. Maybe try some professional training? Either way just watch your baby that is the only way you can really ensure safety.