yorkie poo biting

Question
I recently got a yorkie poo she is 12 weeks old.  the first two weeks she was an angel.  She is doing pretty good on potty training but has recently started biting me.  She nips at my pants and has acutually taken several good bites on my arm and hands.  Left her mouth imprint.  The vet said to give her other toys but the breeder said to grab her back where the mother carries the dog and hold her bottom and make her look at you and say no.  This is not working and I am worried this is not going to end.  99% of the time she is perfect.  She sleeps on my bed for 7 and a half hours has very few accidents but the biting is scarey.  What can I do short of returning her but I cannot do that I love her.

Answer
Merry Christmas Marcia!
First of all Marcia- she is a dog. She is too young to be sleeping in bed with you. Go back to basics and train her before you give her carte blanche in your home...it is YOUR home. You are the alpha. The biggest mistake people make with puppies is giving them too much freedom. Your breeder is right and so is your vet. You must not reward the behavior by allowing her full access to you but put her in time out just like a child. I know it is hard but this behavior can escalate and while it was cute at first, it becomes dangerous pretty quickly. She will start to do it to anyone who comes in your house. Then YOU are liable for it. Not acceptable behavior. Chasing people out the door barking and nipping . I see it alot.
Start puppy classes at the local ASPCA or wherever they have them in your community. Toy breeds often become tyrants because they have big egos and people don't think they can do much damage but they can be extremely difficult to train if you can't train yourself to be disciplined about their bossy little personalities.
She will hopefully grow out of this if you can learn how to deal with her firmly. It is puppy behavior. Get the toys for the switch and bait like the vet says, use the "Vulcan Death Grip" like the breeder says and have a crate or pen for the time outs.
CONSISTENCY is the key- don't give in! The first 2 years are crucial in training.
Good luck and Happy New Year