I would stick to exercises that you sit or lay down for or walk and avoid squats once you are further along. I wasn't even very big and squatted to sweep dirt into a dust pan and hurt myself so bad I could barely walk down the stares and was shaking.
Walk! If you're able to, walk in areas with some slight hills. Also check with your Dr about strength exercises because that will help tone the muscle while burning fat if your pair it with cardio
Hey I think you can't really "target" a certain are, but Power walks will help you maintain a stable weight and will also tone up your legs too. Other than that, do some body weight lunges and squats