"This is awesome, thanks! I’ll probably end up doing something like that but there’s only 1 issue (and it’s what’s causing most of the difficulties) and that she wants to go in as blind as possible, so she doesn’t want to be “spoiled” by watching videos and stuff like that."
She can still go in blind, but it would be your job to sit down with her SOON and find out what would interest he. From there you can make a SMALL plan for the day. I would suggest 2 days for the Magic Kingdom, just because that's the main park and there is sooo much to see, it will take 2 days! DEFINITELY schedule a Character Meal! Depending on her favorite characters of course! I only see one way for you to go...either TRULY BLIND or at least get fast passes for the attractions you think she would enjoy. When I think about the Magic Kingdom, I think of Big Thunder Mountain Railroad, Splash Mountain, Main Street USA, and Space Mountain. Epcot, Spaceship Earth, The Land, TestTrack, and then the countries. Animal Kingdom, Avatar, Tree of Life, Festival of the Lion King, Kilimanjaro Safari, Expedition Everest, and Rivers of Light. I would stay away from the studios since it is a huge construction zone, only a few attractions really not worth using a days admission that could be used on a 2 day at MK! But like most are saying, don't over plan too much and sit and people watch, take an afternoon break and explore the monorail resorts, show her things that she would not normally see back home. If you have time, branch out from the parks and take her to Lake Eola for an afternoon. But whatever you decide, just have a good time!