DO NOT feed her based on her wants. Some dogs will eat all day every day if you let them! Start by feeding her only at certain times with the same amount at each feeding and monitor her weight over time. If she is losing, then up the amount. If she is gaining, then lessen it. I feed mine once in the morning and once in the evening. That's it! Treats are fine as long as you aren't over doing it.
Also, what are you feeding and how much?