A Muslim woman may breastfeed a Christian child
Question

                Can a Muslim woman breastfeed a Christian child? And can a Christian woman breastfeed a Muslim child? What is the Islamic ruling on this child if breastfeeding takes place?.
Praise be to Allah.
    It is permissible for a Muslim woman to breastfeed a 
    Christian child and it is permissible for a Christian woman to breastfeed a 
    Muslim child, because the basic principle is that that is permitted, and 
    there is no evidence to the contrary. Rather that is a form of kind 
    treatment and Allaah has decreed kind treatment in all things. It is proven 
    that the Prophet  (peace and blessings of Allaah be upon him) said: “In 
    every living being there is reward.” 

    Secondly: if breastfeeding takes place, then the Islamic 
    ruling on each of them is not altered by this breastfeeding. Whoever was a 
    Muslim before breastfeeding remains a Muslim afterwards and whoever was a 
    Christian remains a Christian. 
May Allaah send 
    blessings and peace upon our Prophet Muhammad and his family and 
    companions.