Shelter Dog Challenges

Nice article, I adopted a shelter dog two months ago, she was taken away from her owner because of an embedded collar and other abuse issues. She has made tremendous progress in a short period of time. One problem I am having is that she likes to nip and play bite a lot. We have been trying to pull our hands and arms away from her when she does this like the books say and I also have been shaking an empty pop can that has a few pennies in it when she does this and it has helped. Do you have any other suggestions that may help. Also She seems to be suspicious of strangers and sometimes cowers when someone approaches her especially children she has actually snapped at two kids in the neighborhood. How can I make her not be afraid of children. The vet said that she probably was never socialized as a puppy. Any advice. She is a German Shepherd/Husky mix and just turned two years old. Any advice is appreciated.