my suggestion is to stop telling her she is perfect. my mom used to do this and it only made me want to be skinnier because no matter what she said, i still felt like she was just sayn that b/c she was my mom. tell her that if she ants to loose some weight that you guys could do it together. go to the gym or for walks together. try to get her mind off the scale and onto spending some time with her mom. my mom and i have been doing this and we r alot closer and we support each other when we have setbacks. i hope ive helped a lil bit.