If you go to the WDW website and look up the Disability pamphlet (or they will mail them to you, one for each park, but it took me 3 weeks to get mine),
There are links in post #3 of the disABILITIES FAQs thread that takes you to the web version of the WDW Guidebooks for Guests with Disabilities.
That allows you to see the text of the guidebook. When you get to the parks, you can go to Guest Relations in any of the parks.
its standing for long periods of time that will cause her back pain. she may also be in her boston brace which is hard plastic and uncomfortable to wear so between the heat and standing on lines longer then 1/2 hour could be painful .
I just wanted to point out that in most of the lines, you won't actually be standing still. You may for shows that 'load' a lot of people at the same time, but for the majority of rides, the time will be spent moving somewhat. For continous load rides, the line moves forward slowly because they are continually loading people on. For rides like Soarin', that load people in 'batches', you will be standing for 2-5 minutes at a time and then moving forward for a minute or 2 as they select guests for the next 'batch.'
The attractions where you may be standing for a long time are the shows. For example, in the Little Mermaid, once you get into the building (from either the Fastpass Line or the Standby Line) you will be standing for 10-15 minutes in the Preshow room waiting for the guests currently seeing the show to complete their show and exit the theater so your group can enter. Having a GAC would not help with that because you need to wait in that preshow area no matter how you get to that point. All the movies work like that and basically anything that uses a theater works that way too (like It's Tough to Be a Bug). Most of them don't have any benches, so there is no place to sit while you wait.
Knowing which attractions work like that will help you to spread that kind of wait out during the day. Using services like TourGuide Mike will help you to wait the shortest time in line.
Here's a
link to a page that shows the length of the rides at WDW. For the shows, the 'preshow' will usually be about the length of the show, since they start letting guests into the preshow area after the guests who were in that area move into the show area.
The length will also be helpful for knowing how long you will be sitting in the show - as someone already mentioned, the show and ride seats are usually hard plastic, metal or wood. Most either have no backs or very short backs that will not give much support. Knowing how long the show is will help you to spread out the ones that are longer.
If they give me the pass and we could go through fast pass or wait at other places that are shaded. i just wanted the group to stay together not let six go then wait for us to get off the ride 30 min. later.so what i'm asking is would they give me two passes to keep our group together anyone know if they is a # i could call and ask.thanks for understanding her disability.
Other posters did clarify, but just to clarify the GAC (Guest Assistance Card) a little more; it's not a
Pass.
It is just what it sounds like it would be a
Card that tells CMs what sort of
Assistance a
Guest needs. The card is issued to that guest who has a disability and the assistance given is based on the needs that guest has. So, GACs are not passes that all allow one thing; different messages are stamped on the GAC based on the needs of the person.
There is no number to call ahead of time. The GACs are given out at the parks by the Guest Relations CMs, who assess the needs the guest tells them about and give a GAC based on those needs.
One of the reasons for limiting the GAC to 6 is that some of the attractions have limited space - for example, if what you need is a shaded spot to wait, the shaded space may be small, so letting a party of 9 or 10 wait there might mean there is no room for other people who have need to wait out of the sun.
Sometimes the GAC is not needed at an attraction because the needed assistance (like waiting in a shaded spot) is part of the queue. Sometimes the needed assistance is not even available (like the line for the Nemo show at AK doesn't have any shaded areas at this point in time).
And, since the GAC would only be used in the queues, you still have to contend with the sun/heat while walking around. You also have crowds that might be problematic just getting from place to place. We've been 'jostled' much more by crowds walking than by people in lines.
So, although GACs are helpful (and really necessary for some people) knowing where it's busy so you can avoid those places is going to be even more helpful.
hope you have a great trip.
PS - Almost forgot - if she needs a cool place to go for a while or needs to get the brace off for a few minutes/adjust it, etc., each park has a First Aid station with private rooms or cubicles that you can use for that purpose. The location of First Aid is marked on the park maps.
to disABILITIES!
but I guess if the doctor released her, so be it). 
