This is a good question. I haven't read the artifice yet but I think this is up to the child. If they feel they still need the parents support then the parent should go. My parents haven't gone with me for a few years now but now that I'm looking into getting a pump they, or at least one of them, has gone with me to talk to doctors as well. It's about what the child feels. And the doctor should also be supportive if the 20 year old (that's just for example) wants their parent with them!