She will love Soarin’. Nothing uncomfortable there, just a wonderful ride.
Barnstormer and Seven Dwarfs are undoubtedly rollercoasters, but very mild ones. If she wants to try them, she really should. I would prioritize Seven Dwarfs, since it is so much more than a coaster (you get to see different parts of the Snow White story along the way - very cool).
I haven’t been on Flight of passage yet.
Splash mountain will be fine for her if she doesn’t mind that last hill. It is really less steep than it looks from the outside. The “story” on that ride is so great, it is definately my favorite ride in MK, if she is into Disney theming it is worth a try. I would suggest she wears a poncho, though
Unless she really likes rougher roller coasters, I would skip Everest. The same goes for Tower, both rides are somewhat rough to your body, especially the back.