I'd imagine an "elder" person would be someone in his fifties. The Whittemore story is one of the most incredible stories of 19 April . . .
Contrast his story with Pickering's---the Salem militia captain who, had he not dallied so long marching down from Salem (because he doubted the veracity of the alarm, IIRC), could have cut the retreating lobsterbacks off before they reached Charlestown Neck, ensuring that none of them made it back from the countryside alive. Breed's Hill, a few months later, would've taken on a whole different flavor.
Life expectancy from birth was in the 35 to 45 age range. However, infant and child mortality was in the 20 to 30% range.
If a person survived childhood, did not get mortally injured working or in the militia, or get any potentially fatal illness, then they lived into their 60's, and some into their 90's.
I have many ancestors in colonial times who lived into their 80's and 90's, it was not uncommon.
It was, of course, survival of the fittest. Those with genetic defects or "weaknesses" were weeded out by childhood. People usually died of tuberculosis, pneumonia, etc.