That was over 32 years ago in 1989.
Today she is 71, and has starred in 94 movies in total, 77 since Ghostbusters II was released.
In Ghostbusters II, I think Sigourney Weaver looks:
Ghostbusters II scores 6.3 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.