A family member recently found out her child's blood group was AB+ yet hers is O+.

i'm suppose to explain this oddity but i don't know how? so please help me!!!

thanks

My understanding is that is not possible. The only blood groups from an O mother are O, A or B, depending on the blood group of the father, but not AB. The mother would have to be A, B or AB. So I would conclude that the mother is not the child's natural mother.

Unless I have missed something!