there is no way of knowing for sure. an abuser is not going to say yes I abuse my girl and the girl if she is being abused has most likely been threatend not to tell so even if you ask her she is going to say no. Leave it to the professionals to investigate otherwise if she is being abused and the father finds out you talked to her about it he can coime back on you saying you did it and the child being afraid of father will say anything he tells her to. Leave it to the professionals to find out if she is being abused or not that is their job and they have been trained on how to do it with out putting stress and ideas into the childs/parents heads.