Women have the same protein requirements as men. I recommend 1.5-2g per pound of body weight.
Most women have the goals of tightening and toning their physique.
The best protein for them would be a pure whey isolate with no fillers. A pure whey isolate will be essential pure protein and contain only trace amount of carbs and fat.
Whey protein isolate is much easier digested and assimilated then casein. Human breast milk is actually 80% whey. Whey protein is very easily digested by humans.
I personally use the whey isolate wheytobuildmuscle from n2bm.com. A 30g scoop has 110 calories, 24g protein, 2g carb, 0g fat.