Biting issues

Kali is about 10 weeks old now and has been with us for about 2 weeks now. She's a great puppy, pretty much house trained now, goes in her crate with no problems whenever we want her to (supper time, rest time, etc.) and sleeps through the night in her crate every night.

The only issue we are having right now is her biting. I don't mean growling and chomping down on you...but more nipping than anything. We tried the "yelping" thing and that worked a little bit but doesn't seem to be doing the trick anymore.

The real problem is, she is doing it mostly to the kids (6 & 3 years old). The kids are never with her unattended and I try to make sure they don't get her too excited but they are kids and she is a puppy and everyone tends to get excited pretty quickly.

The other day my 6yr old son and I were playing with her...throwing her toys for her, etc. When my son picked the toy up to throw it, she jumped to get the toy but got the inside of his leg instead. Didn't break the skin but it was enough to leave a purple tooth mark. Know, I know she was going for the toy and not trying to bit him but at the same time...6 inches higher and we could have had a real problem.

She tends to nip at the kids fingers when they try to pet her...she doesn't do that to me anymore...usually just the kids. So, this morning, while my son and I were sitting on the floor with her I was telling him to put his hand down for her to smell and lick before trying to pet her. Then, out of no where she lunged at his face and got him in the eye...luckily I think it was her nose that got him and not her tooth.

Any suggestions as to how we can get control of this...and quickly?
I don't want to have to tell the kids they can't play with Kali but at the same time things could have been a lot worse on both occasions and I'm not willing to take a chance that we won't be so lucky next time.

Thanks