I'm sorry you have had to deal with this because no good friend (or anyone, really) should ever discuss someone's weight, especially so negatively.

I know multiple people have pointed this out to you, but just to add in one more opinion, this is NOT okay in any way, shape, or form. There are so many negative messages that she passive aggressively communicated to you in that one statement.

I think this is a great opportunity for you as a friend. I know you said you will let her know that she can't say those things to you, which is great. Maybe this will be a learning experience for her in that she will learn that comments like that hurt people and are not appropriate.

I have had weight issues throughout my life and once had an eating disorder, so messages like this hit home for me. This obsession with weight and fear of fatness has been going on for far too long and has done and is still doing major damage to people in many, many ways. Although we are beginning to see more body acceptance, there is still a very long way to go.

Sorry, I am a prospective eating disorder PhD student so when I get the chance to speak out from that perspective I always do.
I hope you are feeling body positive despite her comments, and I hope you are feeling some clarity and validation from all of these wonderful replies to your post. If you need someone to talk to about this I am always available to talk!