Train the dog. A dog can learn and be trained at any age. It's a stupid myth that older dogs can't learn new behavior. Get some book and train the dog or tell your sister to act like a decent human being and take the dog with her. It's not your job to care for the dog 100% of the time. If you need help training the dog pm me and I can help you. The dog needs to be trained, it's not healthy for a dog mentally to be suffering from anxiety and not live like a dog. What do you mean by you can't crate train the dog because it doesn't know commands? The dog doesn't know commands because your sister didn't bother teaching te dog and if she did she was using outdated/idiotic methods to do so. Work with the breed and personality of the dog. I feel pretty bad for you and the dog though.