Responses
But her specific behavior was to demand perfection-- which implies a whole different set of pathologies-- at least in fiction.
That's possible, because that woman asked her if she had a child and if she has every experienced labour pain she responded by saying that she doesn't have a child. She never said that she didn't give birth. So maybe she did give birth to Kyoko, but after that didn't consider her as her child?
I think Kyouko's mother acknowledges that she was never a "mother" to Kyouko in the sense of a loving, female, parental figure. Given her adversion to Kyouko from the beginning, it's possible that she has a psychological disorder like Postnatal Depression or Parental Alienation Syndrome which blocks parents from being able to properly bond with their children. Sadly, this is a very real thing.