If she is trying to lose weight I used Hyponidd (for a while) Honestly, diet and exercise. There is no easy fix. There are things that may assist a little, but nothing like diet and exercise.
There a lot of different things that you can use, Vitex, is the most popular herbal one, tho it's mostly for fertility, and Metformin (which is a Rx) is the most popular weight loss one. Hyponidd is an "herbal metformin" If she isn't trying to get PG it really is best that she be on a lo-dose BCP. Like Yaz or Diane. If she isn't the chance of developin and keeping cysts is really really high. Also the BCPs will mask the "effects" of PCOS until she can get her weight under controll, or at least coming down.
Much love!
p.s. Everything I just said, like everything in the PCOS world is much and hotly debated. so I'm sure that there will be someone along that argues and tells you (or me) "Nuh-uh!" But I'm due in May, so I must have done something right!