My husband went through the same thing last November, and we were given the directive to do an "ultra low fat diet" but not much guidance as to what that meant, unfortunately (I was surprised and frustrated by this!). We were not given a "limited dairy" but just told to stay away from fat.
Basically, I started reading every single label on every ingredient, to try to keep the total fat content (per day!) down to 10% to 15%. And note the serving size--some things may seem "low fat" but if you eat them in a realistic serving size, you'd end up with too much fat in the diet.
We ate a lot of beans and rice, with stir fried or sauted veg (using non-stick cooking spray or 1/2 to 1 tsp oil). Lentils are also good with rice or beans.
We ate a lot of of chicken cooked in broth or 1 tsp of oil (measured with a measuring spoon, not guesstimated!); season it up with seasonings to help add flavor. You can do chicken & gravy type things, but only if you use 99% fat free cream of chicken (or mushroom, etc) soup, maybe thinned w/ some broth.
And a lot of spaghetti (read the sauce labels, especially, as well as the noodle labels, though--a lot of spaghetti type sauces have a lot of fat in them; we were able to find one brand that had only 2% fat in the sauce).
Another thing that helped was cooking with TVP (textured vegetable protein)--it is very high in protein and very low in fat. It can be substituted for crumbled ground beef in recipes and has sort of the same texture. So I did following recipes with TVP in place of ground beef:
* Stuffed peppers
* Tacos/Mexican (skip the shells or wraps though--those often have a lot of fat in them; I was only ever able to find 1 brand of burrito wraps that had 5% fat per serving and the other brands were higher)
* Spaghetti
* Vegetarian chili
Really, subbing TVP for the meat helped a lot in our case. You can get TVP sometimes in the baking section of the grocery store, near the specialty flours (the kind we bought was Bobs Red Mill, I think?), or in the "vegetarian section". If you can't find it in your local grocery, ask, or try the Whole Foods nearest you. I'm sure you can order it online, too.
You might check out the Boca Burgers/Morning Star burgers or crumbles, or using tofu (not sure about the fat content on those, but worth a look!). There is also a fungus based (I think like mushrooms?) protein called Quorn that you could try. I've only ever seen it at Whole Foods, though.
Veggies--we ate a lot of steamed veg or raw salads, with only fat-free dressings. Some of the veg in the freezer section come already prepackaged in steamer bags, but be careful, if they have any sauce or seasonings, to check the fat content. We used garlic powder and/or fresh ground black pepper on the steamed veg to add flavor.
My DH started eating non-fat greek vanilla yogurt and a small bowl of Kashi cereal (which has very very little fat) for breakfast. Oatmeal and non-fat milk is another option, though most cereals are pretty low in fat, especially if you eat it w/ skim milk.
For sweets, get fat free jello and fat free pudding. I think I've seen 0% or very low fat frozen greek yogurt in the freezer section, though we haven't tried it out. She might be able to do a fat free smoothie by using this recipe: 1 or 2 T fatfree instant pudding powder + 1 cup skim milk + 1 cup frozen fruit (we like berries) + 1 T honey if desired; blend all ingredients until smooth.
Edited to add: I asked a similar question back in Nov, and maybe some of the answers from that post would be helpful for you? Here is the link:
http://www.mamapedia.com/questions/11121788856809226241