The following is not a medical advice, just what I personally do for my similar problems:

If she is doing everything right and she still doesn't lose weight, I'd check the thyroid. Also, for some women especially, if the estrogen levels are too high (and usually if you have PCOS, you have high estrogen), a reduction in calories might be needed, not just reduction of carbs. For me, who I'm small framed, if I eat more than 1200 calories per day, I don't lose a gram.

Regarding a Paleo-ketogenic diet (not plain keto), I think it will help lots. I have a few gynecological pains myself that are going away when on less than 40 gr of carbs per day for over a month (25-50 gr of carbs per day is the goal I keep). I also take a grapeseed/pomegranate/trans-reservator extract, and a curcumin extract, that helps with inflammation in these body parts (and they also lower estrogen).

And of course, it's not just what you remove from the diet, but also what you add: bone marrow broth, offal, coconut oil (very important in the keto diet), sea vegetables, live sauerkraut, and home-made goat kefir. If your patient doesn't go out much either, she should consider supplementing with 5000 IU D3 almost daily (which also lowers estrogen btw, among other major things it offers). These are not optional in my opinion. It's what I do to myself to get healthy from similar ailments. My superfoods: http://eugenia.queru.com/2012/03/05/top-10-must-eat-paleo-foods/

Regarding fertility btw, no matter what you might hear about dairy in Paleo sites, home-made GOAT kefir (24-36 hour fermentation, which means very little lactose, and different casein than that of the offending cow dairy), is the top "drug" you need: http://www.scientificamerican.com/article.cfm?id=real-males-eat-yogurt Kefir is 5-10 times more potent than yogurt, so as long as your patient AND her husband eat kefir, I'd expect good baby results. But it MUST be home-made (store-bought kefir doesn't contain all the needed yeasts and bacteria because of bottling regulations). More info about kefir: http://eugenia.queru.com/2012/04/19/a-word-about-kefir/

If she's trying to get pregnant (and if her doctor is ok with this, don't take this reply as a medical advice), she might need to supplement with folate (not folic acid, they're different) a few times a week too, about 3-6 months before she conceives. Especially if she goes low calorie Paleo-keto, where folate becomes less common in the food. http://chriskresser.com/folate-vs-folic-acid

I'd highly suggest she keeps a food blog, like on fitday or on Chronometer.com, to see which vitamins she's missing. Then she could supplement accordingly (but not overdo it of course, D3 and Mg are the most important ones).

You might find some useful info on Pepper's websites:

http://www.paleoforwomen.com/

http://paleopepper.com/

Many women with PCOS need not only to watch their carb intake, but their fat/calorie intake as well.

What has been working for me is very low carb, moderate protein and high fat.

There have also been other helpful tweaks; giving up dairy helped, as did adding coconut oil. Now that I have lost much of the weight, I do ok with adding an ounce of almonds and a cup of berries daily.

I have PCOS and was on metformin until recently. I had issues with metformin in that it made me crave carbohydrates and made animal protein unappealing. I also had to be prescribed waterpills. It was kind of a mess. I was prescribed the metformin to increase my insulin sensitivity, but I have decided to stop taking it and manage it through Paleo and Crossfit. This seems to be working well for me, albeit very slowly. If she drops the weight, the disorder does reverse, but therein lies the problem. She will have to increase her activity. I'm not saying she has to up her sessions to everyday, but doing stuff like walking a couple miles outside more than once a day, or more time working in the yard in addition to regular workouts.

You might want to talk to primalgirl.com she seems to have figured it out.