Hi. We have a great DISabilities here on the DIS that can answer a lot of your questions:
http://www.disboards.com/forumdisplay.php?f=20 You are welcome to go over there and read and if you register you can ask questions and get advice there. There is an extensive FAQ there you may find helpful.
The short answer is no, you will not be able to get special FastPasses or Front of the Line Access for most of the rides just because she uses a motor
scooter. Most all the lines at WDW are able to accomodate the
ECV's (scooters) and you are expected to go through the lines with everyone else. There are a few exceptions.
If she has other health issues then you may be able to get her a Guest Assistance Pass that might allow her to bypass some lines, or offer her an alternate place to wait while you go through the lines. These questions can best be answered on the DISabilities board I linked to above.
If you need help registering let me know.
