If you need more than one accommodation that a GAC can provide they will stamp it accordingly. So if you need 2 things, they will give you one card with 2 stamps. You will not need a card a for each need ( which is what I think you are trying to figure out).
That is correct.
And, I would not put specific information about GACs in your story.
People expect to get whatever they read about and specific things you write may not be how things are handled by time time your story is read.
We ask posters not to post specific names of stamps, descriptions of stamps or exactly what happened to them at specific attractions for Guest Assistance Cards (GACs)
Some of the reasons are:
WDW can and does change the Guest Assistance Card from time to time. Sometimes it is what it or a specific stamp is called or looks like. Sometimes it is how it works.
And, things you may not be able to see can change how guests are handled.
This can include things like staffing at an attraction, how busy the park and that attraction are, time of day and time of year and how many other guests with special needs are waiting,
How a particular GAC is handled may not even be the same on the same attraction on the same day (even for the same guest).
People tend to read things other people posted and ask for the same stamp, whether or not it is the one that best fits their needs. Guests need to be prepared to explain their needs to Guest Relations.
These are some of the reasons why we ask people not to post the names or descriptions of stamps or exactly what accommodation they were given.
The informations about GACs in post 6 of the disABILITIES FAQs thread is up to date and accurate. It is based on the ADA and is general enough to not give a lot of information that is likely to change. Someone who knows that they need to explain their needs, should be able to get the assistance they need.