We adopted a 4 yr old yellow Lab a year ago. She was kept in a barn/kennel being used for breeding. We are having a problem with training. She wlll not sit or lay down on command. When we work with her she just stiffens up. She is still edgy about certain things like taking treats for us, sometimes avoiding being petted. Sometimes she will and sometimes not. She has made herself at home, loves to go for walks, car rides, has a great disposition. She follows us around the house. Evidently something happen where maybe she was grabbed or lured at times and this surfaces in her mind off and on. We want to help her get past this and feel at ease and not have these fears. We are trying to socialize her by taking her to stores and walks but in stores her tail is between her legs. Her behavior is back and forth. Any advice?