How do you feel when someone calls your baby fat??

My mother, his grandmother. Keeps calling him fat & says he has cankles.... also anytime she comes over, she has at least one little insult. I dont know if meaning too but one time we were working on rolling over and she said "you cant do that you cant roll over" (after she left after a nap we tried again & he did... & then she said ive created a monster he cries everytime she holds him. She doesnt come over often maybe 4 times since hes been born. Just p.o. that how she talked to me growing up & ive confronted her about talking to me that way bout 3 months before he was born & in one ear out the other... I dont want him around that negativity... idk what to do..