Lab scared of almost everything

Question
Hey there,its been 2weeks since i got my lab,Flexy.She's going to turn 1 on 30th sept.she has grown very attached to me and gets excited to see me.but she seems to be afraid of everything.when i walk her in the neighbourhood without a leash she would get scared of a cat or if she saw some chickens ahead of her she will completely stop walking and sit if i call her a couple of times.Shes also very sensitive to sudden movements and becomes very submissive in the presence of my other siblings.but when i get a few friends over she will put her tail between her legs and sit and won't respond, and if she does respond she'd do it in a very submissive manner.I haven't been harsh with her ever.My aunt has her brother,Cooper who is her exact opposite and loves company around.

Answer
Don't coddle her when she shows fear.  Remain matter of fact.  Greet your friends warmly.  Control your emotions around things she fears.  If you tense up, she will interpret it as whatever causing the problem and that will confirm her fear.  

The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/ For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm

Do what you can of these bonding exercises meant for younger dogs.  

''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.