She probably lived in the country and, as such, had a low stress lifestyle. Stress, IMHO, plays a much bigger role than anyone in the medical profession will admit. Take a look at a cemetery in a city, then look at one in the country. In the city you'll see lots of people who died in their 40's, 50's and 60's. The one in the country will have lots more folks who died in their 70's, 80's and 90's. (and the ones in the country regularly ate bacon, eggs, gravy, biscuits and other stuff that is supposed to kill you)
There was no such thing as retirement. If old folks were too infirm to work the fields, they would still care for the children, cook the meals and knit clothing.
I'm not so sure that the rural lifestyle is less stressful-- just a different kind of stress. Rather than being concerned with extracting their daily bread from their fellow men, they were concerned about extracting it from rocky soil, unpredictable rain, wild beasts who could chew down a summer corn crop, etc.
There was much more reliance on the Lord and your own efforts and less on getting your fair share from employers, workers and the like who didn't feel a sense of shared fate with you.
It is just another reason why you find conservatives to be generally happier and better adjusted than their liberal counterparts.