Need diet help with Dolly

I need some help with getting Dolly to lose weight.

A couple weeks ago, I took Dolly in for hip x-rays and her hip dysplasia is worsening quite a bit. One of the first things that will help her stay pain free is if she can lose some weight, which she desperately needs to. 

So let me first explain what we feed, how much, how often, etc., and exercise, and then maybe some of you can see something that I'm not seeing that we can do to get her thinner.

Dolly currently weighs 133 lbs. The vet said he would like to see her a lot closer to 100 lbs. and I agree, because she's very small for a Saint.

We feed Diamond Naturals Beef and Rice in the morning, and RAW at night.

In the morning, she gets just under 2 cups of food. Then at night, she gets a chicken quarter. (like the drumstick and hip section)

I'm going to guess she gets 1 dog treat every 2 or 3 days. Certainly no more than that. No table scraps whatsoever.

We walk her everyday for at least a mile. She has access to the yard all day so she can move around and run, but she mostly chooses to sleep. Now I need to mention, in the exercise thing, she is limited some by her hip dysplasia; we can't go chasing frisbees at the park or anything. Loose leash,relaxed walking is the basic exercise she is physically able to do.

I'm looking into some Lite Dog foods as well, try one of them, a friend mentioned putting green beans in the dog food so Dolly would fill up on those instead of just kibble? I'm willing to try just about anything right now! We DO have a treadmill, and I will be working her on that too.

Sorry this is so long and thanks to everyone for any advice.