I have found that for pcos going high protein and low carb has worked the best for me. I drink a lot of protein shakes! I just make sure they are super low carb and I'm getting at least 30 grams of protein. My favorite are the chocolate ones from Costco (not the "weight loss shakes") but there's one that just says protein shake, 30g protein! Those are my favorite go to meals when I'm on the run. I also have a scoop of protein powder, 4 strawberries and some ice and water every morning when I don't have time to scramble some eggs. I hope this helps you!
I love protein shakes! I've been a trainer & bodybuilder for 10 years now so I'm sure I've sampled more than my fair share of flavors and brands, but I do recommend to my trainees (and myself) to eat whole food as much as possible. With that being said, protein powder shouldn't hurt anyone's weight loss. Quite often, most women don't get in the necessary amounts of daily protein anyways so it would help in that regard.
I think its a good way to get in a quick source of protein before school, before work, etc. Its better than getting in 200+ calories from a Snickers bar or some other processed junk you could grab in a hurry. I'm talking about a low-carb whey protein powder here (not crappy meal replacement shakes which are half sugar and a bunch of sweeteners/fillers). I used to do protein powder with plain water and now I add a cup of unsweetened almond milk.
I've used it as both a meal replacement (for example, 2 scoops with some brown rice cakes) or normally right after a workout to get some liquid nutrition right into my muscle cells to start repair/recovery after hitting the weights at the gym. LoL--Clearly by this lengthy response its obvious I like protein!