Do you two talk about her mother and her death at all? Maybe it would help a little if you got a male therapist so your daughter would not have to unconsciously "worry about" if she got close to another female, they would die like her mother. This is Just off the top of my head; my mother died and I had to deal with it in therapy; there's a lot of unconscious stuff that goes on that can take a long time to work with and treat. I would try to do a heart-to-heart talk with your daughter, see if she can help you help her? It has to be very difficult for you too, I imagine but if the two of you can help each other a little, be there/present for each other, that would be what I would want.