That was over 24 years ago in 1997.
Today she is 71, and has starred in 94 movies in total, 66 since Alien: Resurrection was released.
In Alien: Resurrection, I think Sigourney Weaver looks:
Alien: Resurrection scores 6 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.