I watched this cartoon around 1997. It's about kids who use robots to fight, when they fight they are inside the robots standing and whatever moves they do the robots mimic them. In the last episode that I watched and remember there were three kids and they were discovered by an older woman who introduced them to the robots. It was in an anime-like style.
Evangelion maybe? It was a cartoon series made in Japan in 1995-6 and then the first movie came out in 1997. Definitely anime style. The plot involves hostile supernatural aliens called 'Angels' attacking Earth. Earth is defended by a secret U.N. taskforce called 'Nerv', which is made up of young teens who pilot giant bio-machine robots called 'Evangelions.'
Link to info about the cartoon: https://en.wikipedia.org/wiki/Neon_Genesis_Evangelion
Neon Genesis Evangelion is a Japanese mecha anime television series broadcast on TV Tokyo from October 1995 to March 1996. Evangelion is set fifteen years after a worldwide cataclysm, particularly in the futuristic fortified city of Tokyo-3. The protagonist is Shinji, a teenage boy who was recruited by his father to the shadowy organization Nerv to pilot a giant bio-machine mecha called an "Evangelion" into combat with alien beings called "Angels". The series explores the experiences and emotions of Evangelion pilots and members of Nerv as they try to prevent any and all of the Angels from causing another cataclysm, and as they deal with the quest of finding out the real truth behind events and organizational moves.
The End of Evangelion is a 1997 Japanese animated science fiction film written and directed by Hideaki Anno and animated by Production I.G. It serves as an alternative ending to the Neon Genesis Evangelion television series, in which teenage Shinji Ikari pilots Evangelion Unit 01, one of several giant cyborgs designed to fight hostile supernatural entities called Angels.
when they fight they are inside the robots standing and whatever moves they do the robots mimic them
sounds exactly like G Gundam, however I've never watched that show so I can't confirm.
This is what the cockpit of the Gundams in G Gundam look like (EP05)
It's probably not Evangelion (in that show the kid pilots use more "cockpit" style controls).
Cockpit of EVA-01 from Evangelion 1.11 You Are (Not) Alone
Also it doesn't really fit your timeline because G Gundam didn't air on American TV until 2002.