It means there was a ceremony in which the woman was "blessed" after giving birth. It varies from religion to religion as to when its done...its usually anywhere from 20-40 days after. Its not widely practiced anymore.
In Christian tradition the Churching of Women is the ceremony wherein a blessing is given to mothers after recovery from childbirth. The ceremony includes thanksgiving for the woman's survival of childbirth, and is performed even when the child is stillborn, or has died unbaptized.Talking about their own church