I am so sorry to hear that and your family will be in my prayers. I doubt there is nothing much you could say to make her feel better, just let her know you are there for her and stay by her side.

When my son died, there were two people I will never forget that came. One was a neighbor who came and sat quietly on my sofa and every hour or so, she got up, washed up the dirty dishes and made fresh coffee. After the funeral I had someone ask me who that dark headed lady was that stayed by my side and I didn't know, I had to think about it and when I did, it dawned on me there was a friend Francis that I knew that seemed to always be there, that quitely stuck to my side but out of the way that tended to my every need.

The biggest impression was a SIL that came and told me she needed me to go with her and took me out of the house, put me in her car and said "I am here to just take you out of here to give you a quiet break away from everybody, where would you like to go?".. I will never forget that kind act and break that I so badly needed but just didn't know it. It is those things that really impressed me and showed me who my friends were.. the quiet ones that were there to help without being noticed.