"What do I say to her to tell her I don't want her making those kind of comments because I feel it is not necessary and I feel quite upset over it."

That sounds good to me. How about just saying that? And when she comes back with "Well, I just don't want you to have saggy boobs" or whatever, you just repeat it. They call it "broken record" technique. "It's not okay for you to make those comments about my appearance." "I don't want you making those comments about my breasts." "I am upset that you keep making comments about my breasts, and I want you to stop." You just keep repeating the same idea over and over, until eventually she gets the message.

Your anger is a signal that you need to stand up for yourself.