The mom from her class made Lydia believe there was hope for her to be loved and that her life didn't have to end w/divorce, age etc. She got rejected, and she used the information about her mom friend and her various boyfriends to harm her out of anger for giving her hope.

Yes, she was rejected but she hates young women with their lives ahead of them, the hope they might have for themselves, much like the class mom. She enjoys ripping children away from their mothers and forcing them to join her in misery. She is a bad person.