normal behavior for yorkie puppy

Question
Hello Ive just recently purchased a female yorkie puppy, not our first, we also have 2 males and they are wonderful.
Im just curious our new little addition is really spunky.
She is 12 weeks old and wants to bite on our hands all the time and really never wants to be held. She is always so curious about everything. She so wants to play with the others but I think their going thru the " Im mad right now stage,but are warming up slowly. Is this normal behavior for a puppy to want to bite all the time and hardly ever any kisses. She is not shy at all, loves everyone and seems to play just fine. Im just worried she will become a terror. She also sleeps all day, I would to with her activity.Is there anyway to stop the nawing at our hands when she doesnt want to be held or is this just the way she plays and is she going thru teething or something.Will she always be aggresive if I let her continue?

Answer
The Yorkshire Terrier was bred to go to ground after animals three times their size...they are TERRIERS.  You may have "lucked out" in terms of temperament with your males.  Your female, however, seems not to have been properly socialized to humans as a neonate and appears also to have not learned (perhaps because she had no littermates or a single littermate) that using teeth HURTS.  You don't describe how she interacts with your other two (that would have helped) so I'm assuming they are tolerating her.  Because she is so "bold", I suggest you begin to insist on "holding" her on a daily basis for very short intervals.  Pick her up, hold her gently, ignore her protests (no matter what they are) and when she settles, put her down.  Repeat this until she settles immediately; then insist on holding her for several seconds multiple times a day while offering her a tiny (very tiny) treat (small piece of cheese, chicken frank, etc., but very tiny) so that she learns "confinement" in human hands is rewarding and must be tolerated.  If she mouths you (uses teeth during play or any other time) yelp loudly  and move away.  At this point, her mouthing is a function of her not knowing that using teeth hurts; yelping and moving away (removing yourself is a huge non-reward for a puppy) should help her learn that.  If for some reason she persists even after you've used this technique repeatedly for more than ten trials (episodes), pick her up and hold her and when she settles put her back down and offer her a stuffed toy.

I also strongly suggest you learn about positive reinforcement training and begin to teach this dog simple behaviors.  Once she has securely acquired 100% response to one command, make her earn everything: going out, coming in, being played with, being petted, etc. until she's about nine months of age (or first heat cycle.)  This "Nothing In Life is Free" regimen should help her understand that she is quite low in the pecking order of your "pack" and should contain any rank opportunism she might experience.  I certainly hope both your males are NEUTERED because YOU DO NOT WANT to breed this puppy!  However, spaying should be delayed until six to eight weeks after her first heat cycle, as she appears to need the progesterone component.  

If you have any further problems, please repost.