Disability

the attorney is only protecting himself, you, and your Mom. There have been plenty of elderly with dementia, who were exploited by their children, spouses, guardians, etc over the years. Your brother, or another relative, could cause a lot of problems and accuse you of manipulating your Mom. So think of it as crossing your T's and dotting your I's. So if someone wants to make a case that your Mom was not in full mental capacity, you will have a piece of paper from a physician stating that she is mentally competent to make financial and life decisions for herself. The attorney has given you some good advice.

You don't say who you want to write and email. I assume it's your brother. Does he need to know why your Mom goes to see a doctor? If he asks, I would just say that she went in for a check-up. If he wants to know more, he can ask your Mom. And she can tell him, or not, as she pleases.