It depends on many factors. Does she have any medical conditions that might interfere? Can she handle some bumpiness with rides? Are big explosions and gun shots too much? Keep those questions in mind, as they will help you debate. USF, overall, is a better choice for older people because it's not as rough as IOA. Then again, I once saw an older lady (I'd guess 80s-90s) climb out of the boat at River Adventure. The boat behind her was full of teens and they were cheering her on. I also heard from a Dueling Dragons employee that a grandmother (same age bracket) was with her family and rode Dueling Dragons. The same result there-when she got off, lots of teens/young adults were cheering for her.