[JoeyP]

This sounds very much to me like a puppy that is showing aggression out of fear
and it's not surprising that it's coming from a puppy that has been purchased through a puppy store
you don't know the history but it's very likely she was taken too early
and thrown into a situation where there are no little mates ... sterile conditions with big people always coming and gawking and grabbing at her

This is the perfect set up for this type of behavior
What a puppy like this needs is a very strong loving leader
She needs to make up some lost time in her social skills
and she needs to be shown that people will not be something to fear

With a puppy like this it's best not to use your hands to grab her esp from a standing position
it's best to call her with a treat
when you want to pick her up crouch down to do it it's less threatening that way
Try holding her and even sleeping with her if you can as much as possible to strengthen the bond
and make sure that food isn't an issue
make sure you handle her food as she eats it so no food aggression takes hold