By what you say ,it seems to be a kind of behaviour exhibited by your child,which is harmless as such,another thing could be medical condition 1.where in lower jaw might be small ,to accomadate tongue ( micrognathia with falsely appearing large and protruding tongue(macroglossia)) 2. primary macroglossia (large tongue with a tendency to keep it out) 3. regarding bulging lower lip,it could be due to constant pressure by her tongue and her taking out of 2 teeth from lower jaw at 2 1/2 month with her tongue, looks like natal neeth (as child was 2 1/2 months when it happened) which usually have no deep root and can cause lot of irritation, cranky behaviour for children, which basically has come out due to her maneuvours and i feel it is not of worry because the primary teeth which is yet to appear around 9mnths-1 yr are stronger and wont fall off just by her tongue i hope i was of help...if you still have queries you should visit a dentist ,to get her checked for any other natal teeth left,cause their accidental fall and consumption can cause choking in child and also by a family and developmental pediatrician to assess her general growth and milestones thank you