Jog Sound

I rescued a mixed dog (cocker spaniel and border collie) when she was 5 mths old. She came to me with a urinary track infection, parvo and only has three legs which i believe she was hit by a car when she was small puppy because she will not cross any road that has cars on it even while on a leash. She lives with her step brothers Pepper and Cowboy ( cocker spaniels) and they bark at any and every noise! I thought for sure they would have taught her since they were a big help in the house breaking department! She is now 14 months old and still nothing. Her health is great and has mostly the border collie look and energy and can run faster than any dog with four legs! However, sometimes while she sleeps it seems like she having a nightmare because she shakes and squeals a high pitch whine. Could all of this be related with what happened with her before i got her? It is not that important whether she barks or not I love all my pets.