She encouraged Trouble's inappropriate behavior, which is discouraging to trainers, breeders and rescue people alike. By allowing (and from reports, encouraging) the dog to be aggressive she set up situations for biting.
Many, many people do so accidentally as well. As blasphemous as it sounds, allowing your pet to sleep in bed with you encourages the same type of behavior. I hear from dog owners that their dog has never been aggressive and I understand that, but it does occur often. When one doesn't have 12 million dollars for doggy care and something happens to the owner, the dog is often euthanized. Either the designated caregiver won't put up with the undesirable behavior or if the dog is taken to a shelter, the staff can't get near the dog.
There are simple ways to retrain a dog that a human has allowed to run its environment. The easiest way is to not let it happen in the first place. Check out dog training websites; you may be surprised at how dogs need to know their place in the pack. Dog trainers are worth every penny!