I’m just like your sister, no fast or crazy rides for me and I love Disney! MK she will enjoy Little Mermaid, Snall World, Pooh bear, Peter Pan, Philharmagic, Country Bears, Ferryboat ride, train ride around MK, Carousel of Progress, Peoplemover, Monsters Laugh Floor, even Buzz Lightyear since you can control any spinning yourself and it goes pretty slow. Plus all the shows and parade she will have a blast. Epcot, I would stick to Figment, Land ride, I don’t do Soaring because not s fan of heights, Mexico boat ride, and just visiting the countries is a lot of fun. Plus they have the Mouse Gear gift shop, definitely a must when there. I find Disney Studios not as fun for someone afraid of thrill rides so I would skip that park for your sister unless she just wants to go see a few shows etc. Have fun!!