Weight is gone but tummy is not😢

I’ve lost 15lbs in 2 months. I went from 149 to 133 with a low calorie diet. I had my daughter 18 months ago and have a lot of extra skin still which I thought i could get rid of through diet but it’s still there and i look the same weight :/.... i have spina bifida and heart problems so working out isn’t really easy for me. Can i burn the fat by continuing to lose weight or will i have to exercise?