It's understandable, though - if you'd consigned someone to the dark depths of the mind, along with all the terrible memories associated with them, would you want to dredge them up again?
It's a kid you haven't seen for, what, 60 years? You wouldn't know them. They wouldn't be your kid.
One might be quite embarassed to see them - you're the mother, yet all you did was give birth to the kid and raise it for a few years. She might not want to face up to the fact that she had virtually no hand in her childs upbringing.