It is wrong to keep important information from people
Agatha agreed to let Nancy use her phone number as a message phone because Nancy's children were in protective services and Nancy was trying to get them back.
Agatha doesn't want to take messages for Nancy anymore.
Agatha tells Nancy she just can't do it anymore and Nancy finds another friend to take phone messages.
Agatha erases any messages she gets for Nancy without reading them or telling Nancy.
Nancy is able to work with protective services and get her children back.
Nancy misses important appointments and loses custody of her children.