Mate.. all you can do is keep telling her.. lol.. that's all.. just about all the women I know say.. aww I'm too fat.. aww is my bottom big.. aww I have tummy fat.. yada yada yada! And all you can really say is 'yeah you're right..' hehe.. Nah.. it has crossed my lips to my GF a couple of times, She just gives me an evil look lol! Just keep telling her how you feel about her 'You're the most beautiful woman I know, I love all your body and it's the most sexiest thing I know..'
Goodluck!