it also lists renal (kidney) failure.
Ischemic strokes can be caused by very small blockages in blood vessels in the brain that are often associated with smoking (among other causes). This happened to my dad, who was a lifelong smoker. I am so against smoking but it's a really hard addiction to break... my dad tried everything under the sun, and even when he could quit for a one or two year stretch it always pulled him back.
It does seem odd that she'd be riddled with cancer and have not detected it via some sort of diagnostic imaging... even if she didn't suspect she had cancer, she did mention her back issues (scoliosis) and one would think some sort of imaging would have been done at some point for that problem if not in an ongoing way at least at one point in time such that the cancer, in what would appear to be many different organs, would have shown up at some point. Who knows.
It suggests she may have had the stroke, been found and rushed to hospital, and just never recovered. If she went peacefully then that at least is a blessing in all this.
As I type this I am looking at her wardrobe road case, which I bought at the auction of her stuff. It still smells of her perfume.