[Tink]

Most often when people are that insensitive, it's a result of something that's damaged them at an earlier time. Maybe she never learned to accept the loss of her own mother and felt disloyal about allowing herself to bond to another one? It's hard to say what motivates people, but now that Vivian is gone, it seems there's not much to be gained by opening that can of worms. The chance for her to show her appreciation has passed with this woman who sounds like she was a very dear lady.