Keep pampering her and show that you love her fat by keep telling her that you do, touch and play with her belly, etc. If a woman likes you, then she'll grow to be fine and even like herself. 2 of my past girlfriends (both chubby) were like that; both initially hated their bodies and grew to either feel neutral or even like their bodies.
Most women hate their bodies, skinny or fat, and part of them liking themselves is if their man likes their bodies. Not just for sexual purposes, but truly love it. Worry about the feeding and fattening later, and focus on getting her to be fine and actually like aspects of herself. If she knows you love it, you can condition her into loving it too.