New pet

My son decided he wanted to adopt a new dog to be a companion on his hiking/camping trips. We stopped by the animal shelter a couple days ago and he fell in love with one that appears to be at least part Shepard. He brought her home for a trial and has decided to keep her. He changed her name to Sierra which was a much better fit than Penny. She came from a hoarder who had 27 dogs. Her only problem is that she grabs anything that isn't bolted down and claims it as hers.I am suggesting my son look for a local dog trainer before he takes her too far away.