Oh geez I forgot who said about their daughter having PCOS, I would really recommend you take her to the GP to get checked, the sooner its sorted the sooner she can get her head around it if she does have it. Its all well and good saying that 'she is still young' but feeling that there is something wrong with you and noone is listening to you, is one of the worst things when you are younger.
I battled with my GP for 2 years since i was 13, as I never had a regular cycle, I always had extra hair, spots, over weight (well medically obese), and all he would say was 'lose some weight', thats easy to say, but with pcos comes insulin resistance (PCOS for Dummies is a fantastic book to read btw). It took 2 years to get refered onto a gyna, even that only took off because my period would some twice a month, or once every 5 or so months I got threatened by a pregnancy test by my mother!, and then I got diagnosed with it just before I turned 16.
First pill was Dianette but it made me so depressed, got put onto Yasmin which reacted with me alot better, have been put on Metformin since Oct last year however only started losing weight in Feb this year.
If you have excess hair, i suggest you go get checked for pcos (i forgot where it said, i think it was bbc website, that 70% of women with excess hair, have pcos as the underlying problem), also alot of the time women get diagnosed with diabeties type 2 is because they had undiagnosed pcos so they couldnt catch it early and prevent it.
GI diet was fine, I did it a few months before a holiday, lost 2 stone, however during my holiday I left it, and got lazy, never wanted to restricted my food, and gained the weight incredibly quickly without realising it (thats one major problem with pcos, you gain so easily). On Paul Mckenna at the moment since Mid Feb and lost 16lb, i'm finding it alot more easy going than I ever found the GI diet.