That was over 37 years ago in 1984.
Today she is 71, and has starred in 94 movies in total, 83 since Ghostbusters was released.
In Ghostbusters, I think Sigourney Weaver looks:
Ghostbusters scores 7.3 out of 10 on The Movie Database.
Sigourney Weaver's first acting role was as 'Alvy's Date Outside Theatre' in Annie Hall, released in 1977 when she was 27.