Most woman who become sexually inactive become sexually inactive around age 65 to 70 years old with the average age of a woman being sexually inactive around 67 years of age.
Some woman continue to be sexually active well until they die which could be 80 to 100 years old.
But for most woman they become sexually inactive and no longer desire or want to have sex after 65 years of age.
But then again some woman have sex well into their 80's and even 90's.
The same is true for men as some men stop being sexually active around 65 years old while other men may be sexually active for the rest of their lives.