Biting Cockatiel

We have a new cockatiel and she is a biter.
We don't know for sure if Dixie is a male or female. The best we can tell is she is a female. We have had her 2 weeks and I believe she was about 3 or 4 months old when we bought her at Petsmart (I know, petstores are evil. long story why we bought her there). I am not a first time 'tiel owner but it has been quite a few years and Dixie is so different from my last bird.
Dixie was a hand fed bird but she is not very tame. We are working on gaining her trust. The biting is making it difficult though. I had one suggestion to let her out of the cage in a safe area and let her play with toys and explore, we have been doing that and working on step up. She will sit on my hand after a little coaxing but will just sit and bite at my hand and arm. I don't pull away or make any sudden movements, nor do I give in. I try to take it as best I can and just keep telling her "no" or "Dixie no" whenever she nips. It hurts but she is not drawing blood.
I am looking for any more suggestions how to handle her. I don't want to rush her because I know she is in a new home and young, but at the same time I don't want to ignore this too long and never have a tame bird.
Thank you

we hand raised hundreds of cockatiels, for the biting, we gently blow in their face to make them let go with a uhuh after it....after awhile they'd stop.

I can't tell if the blowing in the face is working. It just seems to make her mad. She will come out of the cage now and sit on the top, but is still biting. This makes it especially hard to put her back because she will back away from me and bite. She won't 'step up' yet.
Does any one have more suggestions or similar situations?

My friend had a not so friendly tiel before. To get him to stop biting she starting just leaving her hand inside the cage with food in it for a loooonnnggg time (she would just put the cage next to the couch and stick her hand in there while watching her t.v. shows) she would not do anything with her hand (no touching, no sudden movements) just leave it there, and the food would show that the hand is good i guess? Hope that helps!

Clicker training worked for mine. I too bred and handraised cockatiels. The babies were easy, I bought the father from a breeder, but we got the mother from a pet store (I was young - mom bought her for me as a gift). And she was NOT handraised (holy lord, did she ever bite). At first, I could ONLY handle her with a glove, but I basically just let her bite me. It didn't take long before she realized that I wasn't going to hurt her (I was always beyond patient and gentle), and biting wasn't going to discourage me. I also only put her back in the cage after she had calmed down.

She was "tame" after a few months, but after about a year, she was still not where I felt she should be, so out came the clicker (which at the time was an old snapple lid, or a click of my tongue), which eventually led to her allowing me to give affection (she loved being scratched under her wings). It took a while, but the clicking really helped.