What is your impression of Mme. Simon?

Mme. Simon says at one point that she is nursing Félicité because she knows that one day she will get sick and die too. This sounds at first like a cold reason to be with her, like it's self-interested. However, upon reflection, she certainly can't expect Félicité to sit with her because she'll be dead and so perhaps it's really just an act of empathy. If that's the case, then Mme. Simon seems like a very nice person. It is certainly lucky for Félicité that she's there, so maybe her motivation doesn't actually matter as long as she's there.