Priscilla Presley was 34 in This Is Elvis when she played the character 'Herself (archive footage)'.
That was over 43 years ago in 1981.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 78, and has starred in 19 movies in total, 19 of those since This Is Elvis was released.
In This Is Elvis, I think Priscilla Presley looks: