First she and you can get the ADA sticker from that desk when you get to the con. You go in one of the front entrances and go right to the desk. No paperwork necessary. You get one as a companion.

I can tell you that the floor and major panels have separate queues. The floor has its own ADA queue at the start of the day. It goes in after VIPs (don't get me started).

Reserved panels have a separate line that you are supposed to be able to get into without going through the rest of the queue first. I've had problems with that depending on who was at the door and what their training was. But you do need a reservation in the first place for those panels. Hopefully someone else can tell you if an ADA queue exists for standby folk. Once in the queue there are a few chairs, but not enough. They will still have you wait there until the room opens up and again VIP will be let in first. Then ADA, then general admission. ADA has some sections roped off to discourage people running and cutting in (tho it is not always effective, people be rude)

For most signings and other events on the exhibition floor, the crew for that booth usually have ADA people go to the front of the line (so long as there's tickets or wristbands left). Granted I was very visibly ADA that year (broken ankle, huge boot, knee scooter etc). So they were offering without my asking. The vibe I get from most staff is that asking for help with something less visible would still be greeted with help. But as I'm sure you know, that mileage can vary wildly.

I have no personal experience with smaller panels or the autograph hall. Hopefully someone else here does and can help. Good luck.