A Child’s Religion (Hadith No. 1137)
A young Jewish boy used to serve the Prophet and he became sick. So the Prophet went to visit him. He sat near his head and asked him to embrace Islam. The boy looked at his father, who was sitting there; the latter told him to obey Abu-l-Qasim and the boy embraced Islam. The Prophet came out saying: “Praises be to Allah Who saved the boy from the Hell-fire.”
A child is on his/her parents’ religion, as we get to know from another Hadith. When he’s born, he’s on fitrah, but his parents make him a Jew or a Christian etc.
This young Jewish boy was invited to Islam on his death bed by Prophet (SAW). This means that if he died without accepting it, he would’ve entered the Hell-fire. So yes, children deserve da`wah as well.
What if one of the parents is Muslim? What religion is a child on then? Read more on it here.