Historical Status Of Haleema Sadia
There is nothing wrong with infants being breastfed by women, whether related or otherwise. In fact, Quran has given us a Sharia in this regard where it goes further and establishes a relationship of milk-kinship with woman who has breastfed an infant. You can see the details here: Discussion 29875 As far as the matter of Halima Sadia is concerned, one should note that this is a matter of historical scrutiny, which does indicate that She did in fact breastfed Him (sws). But these matters have no bearing on primary premises of religion, and believing them or not, does in no way effect one’s understanding of the religion and application of that religion in one’s practical life.