Really broad brushstrokes here, but:
Normies can say to themselves "if I was the other person in this situation, I would want x, so I'll provide x" and a lot of the time, what they provide will be what the other person wants, because the other person's brain works similarly to theirs.
When autistic people do that, though, what they provide is very often not what the other person wants, because our brains work differently to most people's.
So autistic people, who, remember, have a social/communication disability and find this stuff harder than the average person would, actually have a much more difficult task than the average normie does, because they can't assume that the other person probably thinks much like they do and wants the same sort of information.
I think OP was explaining the thought process she went through in deciding what info to send and how to send it, not saying that the therapist was wrong for wanting something different. If the average person went through the same thought process ("What kind of communication would I find useful if I were in the therapist's situation here? Okay, I'll do that") they would usually land on a course of action that would work well. Autistic people aren't so lucky as to be able to do that, because we're a small minority. (This theory is known as the double empathy problem and while it has its limits it rings true for a lot of lower-support-needs autistic people.)
A therapist who works with lots of people who think like OP should be able to help her work out how to do the therapy in a way that works for both the therapist and OP.