I guess I see a "best" Friend. What you/she seem to describe is a good friend.
First and foremost my W is my best friend. But beyond that I've had relationships with a few people for most of my adult life.
My Twin brother A friend that I've known since Jr. High A friend I've known since elementary school A friend I've known since high school.
All of these guys are really good friends and have been part of my life longer than my W. I don't "expect" tangible anything from our relationships, but I know I'd get their support, encouragement, etc. anytime I needed it. (I guess that is an expectation) and I would do the same for them.
If fact, I frequently give them legal advice. I do think there is a level of mutual respect, admiration and maybe even some expectations. If one of my friends told me something really nice, I wouldn't just brush it off because of our relationship. It would mean A LOT to me because he has been there through most everything.
If I asked my friend for help and he brushed me off. I would be a little upset - again because we've had this relationship for years and years. In fact, I had a falling out with one of my great friends over an issue, but I didn't just not care one way or the other.
Yeah we don't talk bout our friend Rs a lot, but we have at times. My great friends are dear to me and I love them as brothers. I just felt you and the coach trivialized that notion. I think that's why language is important here.
I understand what she's/you are saying but I wouldn't use the term "best friend." Maybe acquaintance
Patience is bitter, but its fruit is sweet. --Jean Jacques Rousseau.