When Jack dies, Maggie thinks long and hard about whether to renounce her vows a second time and step back into the secular world as Matthew's mother, but while that sounds virtuous in theory (aren't children owed a mother's love and care?), on a practical level there are nearly insurmountable obstacles. She has no guarantee of finding a well-paying job or suitable housing, no guarantee that she and Matthew would have compatible personalities, no guarantee that such a drastic change in her life wouldn't trigger a new mental health crisis, no guarantee she could navigate the maze of special needs education without the support of the Church behind her, and on and on and on.

Perhaps she could have introduced herself as Matthew's mother while still holding to her vows, but she's never been good with in-betweens; in the end, she keeps the break clean.