Hi there!
I've done WDW in a wheelchair and an
ECV a few times, and my best advice is to alter how you plan your days.
If you aim for commando stule touring, trying to get on loads of rides every hour that passes you may feel a little disappointed. Whilst Disney is the most accessible place I've ever vacationed, it takes *time* to do stuff, more so than when walking. If you have realistic expectations you'll feel much more fulfilled.
A wheelchair is a definite, there's so much walking that crutches are a problem. I did
Disneyland Paris on crutches a few years ago and it wasn't fun. I personally don't think you would need a GAC, because the only accommodation you need is wheelchair access and this is standard anyway.
Accept that you're not going to know all the protocol for boarding and standing in line for each attraction - be ready to ask for help with a big smile and lots of pleases and thank yous. Cast members are at the entrance to every ride and will happily direct you.
There are some rides like POTC and Space Mountain that ask you to transfer to a park chair, so you just park your own chair outside and use one of theirs. Remember to put the brakes on when you're on the moving ramp out of Space Mountain!
Finally, remember that doing anything with a cast on is hot, tiring and uncomfortable, so she will probably need more TLC and breaks than she would otherwise. Lots of Dole Whips should do the trick!
I reckon you'll see WDW in a whole new light. Enjoy and have fun, and remember to relax!
