My new Golden

Question
I have just bought a Golden retriever puppy that is 3.5 months old from a local kennel.  When I viewed her at the kennel everything about her seemed normal.  She was playful and responsive to me.  Because she is a little older and never been separated from two of her sibling, however, I think she is now mourning the separation.  If any of my friend's dogs are around she is fine and she acts normally.  If not, she is reserved, shy and will not eat, drink or move from her bed.  How can I help her without buying another dog?

Answer
At that age puppies are much less receptive to new experiences than before 12 weeks.  It will take more time.  Here are some things that will help bond and establish you as leader.  

''Elevation for small puppies: Sit on the floor and gently put your hands around your pup's middle, below his front legs, and lift him up. He is facing you. Hold him for 15 seconds. Repeat until he no longer struggles. If he is past 10-12 weeks, lift his front feet off the ground, but don't pick him up.

Cradling for small puppies: Hold your puppy gently on his back, as you would cradle a small baby. If he struggles, hold him firmly until he quiets for 10-15 seconds. With larger pups, you can do this as your sit on the floor, with your pup between your legs.

Quiet lying down: Place your pup on the floor on his side, with all 4 legs pointing away from you. Use your hands on his neck/shoulder area and middle, to hold him in this position. When he is quiet, praise him. Lengthen the time that you keep him quietly in this position. When he accepts this position well, handle his paws and muzzle, while keeping him quiet.''

The quotes mean this isn't my original work. It is copied from my Puppy Raising Manual. I have long used these or minor variations of them, and they are very effective. You may want to give him a belly rub while he is on his back too. Helps bonding. There is a big difference between him rolling over and demanding a belly rub, and you choosing a time to roll him over and rub his belly. The latter cements your place as pack leader.