It will be interesting to see what the circumstances were. I would not be at all surprised to find out she died of natural causes. A heart attack or something like it, she abused her body so badly that any little genetic predisposition could have been magnified.
But enough of that.
As a singer, I loved some of her work, but was not her demographic for much of the rest. The rendition of Chess' I Know Him So Well, a duet with her mother, I think is far better musically and emotionally than any of the cast recordings. The Greatest Love of All I found inspiring to the point of tears, even moreso now because she sang the words but did not listen to them. Dolly Parton has said early and often that she loves and is honored by what Houston did with her song I Will Always Love You. It took me a while to get there. One Moment in Time may be my favorite of hers.
I don't like gospel, too much shouting and spoken word. I Wanna Dance With Somebody took a lot of stamina, but not a lot else. That was true of many of her songs.
I am very sad that we lost her. But sadder still, we lost her years before she died.