Omg she is driving me crazy!?

Ok here is my problem!

My mother is driving me crazy, she continually goes on about my weight now she is a lot bigger then me and it usually never bothers me but lately she has been bringing it up around other people talking about how we are the same size, wear the same bra size etc….

Also I get the “Do you need that” from her also she has been really comparative about what we eat or how much exercise we do each day, now I have just had a baby so I know I am bigger then I was before but I know I will loose it……….. Anyway it is driving me crazy I have tried the “I will worry about what im doing so you just worry about what im doing” Line but yet she wont give up im happy with the way that I am and I know im not that BIG but after having a baby that is usually the last thing you want people going on about so I need some good advice on what I could say or do to keep her off my back!!