Well, if she wins re-election to another 4 yr term in the coming election, she will start that term at age 91, and end it at age 95.   So far, she is unopposed for re-election.

According to the US Census, the average 90 yr old person has a 4.8 yr additional life expectancy.  That would mean that there would be about a 50 - 50 chance that she would die while still in office.   And who knows how disabled she might become even before that.