To get her back in shape, Lunge her both directions 2 or 3 times. make sure that her head is on the inside of the circle.
Move her hind quarters away from you with her head tilted to you. The back leg closest to you has to cross up and away from you. This will build muscle to lose fat.
Flex her neck around on both sides and pull\massage until she is not pulling on you.
Flex and move the hind quarters away from you at the same time. Her head does not need to be pulling on you as you are doing this.
Back her up in a straight line then yield her shoulders away from you. The front leg closest to you is to cross over the other front leg. Do this at least 3 times.
Do all of them on both sides.
These are exercises that will make her lose weight and she will be able to perform better.