I agree with your points also. What an inappropriate comment to make. The fact she felt it was okay to say makes a statement in itself. What if she says that to someone who DOES have AIDS? Omg, I can't imagine.
You look beautiful and normal. I know that you know that, but that's my two cents.
I agree that we have a distorted view of normal weight, maybe she is just jealous of your success. I have seen some folks who have lost a lot of weight when I had not seen them in a long time and it CAN be a bit startling when they don't look like they did when you saw them last, but the same would be true if my red hair were suddenly blonde when you saw me next. It's still me.
People these days are so desensitized by things they can say on the internet while hidden in the safety of their homes or offices, I swear it is filtering into real live conversations.
And then some people just have no manners or filters.
Just know you are healthy, look amazing and that pic is an inspiration to us all fighting to get there.