The person accompanying someone to an appointment should know what help was actually requested.

Going with someone to an appointment can mean several different jobs, and they are not interchangeable. One person wants a second memory and a list of questions; another wants company in the waiting room and nothing more; another wants you to speak up when they cannot. Stepping into the wrong one, even warmly, can leave the person feeling handled rather than supported on a day when they have little to spare.

Ask in the car park what would help: take notes, ask questions, or simply be there. Check whether they want you in the room at all. Whatever they choose, hold to it rather than changing roles midway.