All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
It is not permissible to bury the children of non-Muslims in Muslim graveyards, whether they are Christians or otherwise. This is because their ruling in the life of this world is the same as their parents. Ibn Qudaamah said in Al-Mughni: “Ibn Al-Munthir said: “The scholars have generally agreed that a child who is found dead in any place in the lands of the Muslims must be washed and buried in the Muslim graveyard, but they restricted burying the children of the polytheists in the graveyards of the Muslims.”
There is no difference – in this context – between the children of the polytheists and those of the Christians.
Allaah Knows best.