Is female with Rh negative blood a problem?

Most of us will agree that Rh negative mother should be problem with Rh positive baby. But I have several instances that mother with Rh negative blood grouping is not always a problem. An old woman who is wife of a doctor and mother of doctor needed blood transfusion at the age of 70 years and surprisingly it found that she is Rh negative. Before that her blood group was not known to her family. The woman is a mother of six children who are now adult. Her Rh negative blood never created problem. She had no history of miscarriage nor any fetal death. All baby delivered normally without Cesarean section. Recently a mother who is doctor of 48 years needed minor surgical intervention and before that her blood group was not known to her. Now it was found that her blood group is AB negative. She is a mother of three children of which elder one is now a student of university. Her all babies had delivered normally and for that she never needed blood transfusion accordingly test for blood grouping was done before. There are other similar instances. But how will we explain these matter. Actually if any lady with Rh negative blood group under goes previous abortion mostly should have a chance to develop Rh antibody due to leakage of Rh positive blood through uterine vessels during the manipulation of termination of pregnancy. Later these antibodies which are IgG type ( in contrast to antibody of ABO grouping which are IgM type) creates problem to the baby ( Rh positive) of subsequent pregnancy by easy passing through placenta . We can tell it otherwise that it is the 'punishment for murdering a baby'. In normal pregancy there should not be any leakage of red cells from fetus to mother blood and in these cases there will be no problem in babies of mother of any type of blood grouping. So, it should be a advice to all ladies who are newly married or who are going to be married, not to destroy or kill their baby in their wombs.