Hi Sara,
Even though I am not qualified to talk about Ayurvedic treatments I happen to be an herbalist specializing in fertility (I work with Chinese herbs which originated from Indians going into China so many of our herbs are the same) and I treat this all the time. It is a very complicated to treat even with allopathic drugs. So when all else fails they find me.
Even though her insulin levels are normal now this a condition that leads to diabetes most of the time so she should really get sugar and simple carbohydrates out of her diet. This is very hard for someone with PCOS because this condition makes a woman crave these things. It is about as hard as asking a heroine addict to stop taking heroine. It is very very hard.
What she should be eating is lots and lots of cooked vegetable, whole fruits (never fruit juices), plenty of protein and only small amounts of whole grains. This means brown rice instead of white rice and whole grain bread rather that white flower. That kind of thing. Mainly she should be eating cooked vegetables and dal but not rice and her Chappati should be made with whole wheat.
She might get her menstrual cycle back with this diet if she is being very strict about it and doesn't eat to much of these foods.