Who is The Woman My Mother Should Have Been from How to Live Safely in a Science Fictional Universe: A Novel and what is their importance?

The Woman My Mother Should Have Been is Charles's idealized version of a mother. He encounters the woman in a Buddhist temple that exists outside time. She is dessribed as calm, otherworldly, and somewhat eerie. Charles finds the woman repulsive because of her unreality, and he cannot wait to escape her presence.