Time-outs can certainly work, but there's a range of techniques you should try first. Exclusion (time-out) is actually a very serious punishment for a dog.
When she bites, she is trying to play and simply needs to learn that she has to play more gently and moderate the strength of her bite. That's why puppies have such sharp baby teeth in the first place - relatively little pressure will cause pain, so they learn from their littermates who squeal and won't play how much pressure they can exert. So you should try to emulate that and the first technique to try is a loud shrill "OUCH", followed by retiring "injured" from the game.
Of course, your pup will pounce upon you again within minutes, but if her game is constantly ended when she puts pressure into that bite, then she will learn (in time) not to exert pressure.
Now some puppies are more determined than others, and if she won't let you retire in peace for even a few moments, then you can "actively" ignore her by following your "yelp" with getting up and leaving the room for a few minutes, shutting the door so she can't follow. Bear in mind that that is a more serious consequence for your pup - because she's just been excluded from her 'pack'.
And then, of course, there is time-out where you put her in another room or in a pen for a few minutes. That is useful when she simply won't give up, or if you getting up and leaving isn't really ideal.
Other things you can try are distraction - to a different sort of game or training session that does not include the use of her mouth; and also replacing your hand (or whatever body part she's after) with a chew toy.
So there's really a reasonable range of techniques you can use to get your pup to stop biting. No single one of them will be successful all of the time with a really determined biter, but all of the time one of those techniques will help. You could find a lot more information on puppy biting, including the experiences and advice given to others who've had determined puppies, by doing a search of the forums using the term "puppy biting" or just "biting". There is also some useful information in this short article:
http://www.boxerworld.com/puppy/biting/