Sheila McCarthy was 29 in 9B when she played the character 'Heather'.
That was over 38 years ago in 1986.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 68, and has starred in 69 movies in total, 68 of those since 9B was released.
In 9B, I think Sheila McCarthy looks: