I have one who wed in Norwich in 1725 and she only had 2 known children, maybe she was about 35 when she married. I found a likely burial in 1768 aged 80, so born c1688. Then again we should never wholly rely on ages given in records, especially ones that have a "landmark" figure age at burial like 70 or 80, maybe the informant estimated their age.
Even now, you cannot trust ages, or many other "facts", on death certificates, as they are only what is known to the informant.
My grandfather died in 1963, he had always told us his birthday was on Christmas Day, and he was a certain age. That is what his son declared to the Registrar.
Nope, he was born on January 9 and his age was about 2 years out! But that was only found out later.
I believe that all you can expect to be true on any death certificate, up to the present day, is .....
Date of Death
Place of Death
Cause of Death
Doctor's Name
Coroner's Name (if there)
Name and Address of Informant (hopefully)
All else is only what is known to the informant, and must be checked out very carefully, if possible.