The first time Renée O’Connor appeared on camera in a swimsuit (near as I can tell) was in the Disney serial MATCH POINT in 1989.
The next swimsuit appeared in Danielle Steele’s CHANGES.
Then there was the docudrama THE FLOOD: WHO WILL SAVE OUR CHILDREN in 1993.
Rockford Files’ 1996 TV movie A BLESSING IN DISGUISE had O’Connor’s character Laura Sue Dean watching herself wearing a bikini in a TV commercial for a product called Sports Quencher.
There weren’t really swimsuits in ancient Greece. The closest thing Gabrielle ever wore to a swimsuit was this interesting item in the Season Five strangeness MARRIED WITH FISHSTICKS.
And recently, 2010:MOBY DICK begins with O’Connor in a bikini (under a pair of shorts) searching for whale song from her boat The Coffin.