First sorry to hear of having to put the dog down. I’m no dog whisperer but, breeds have genetic traits. Or things are trained or allowed to grow. Sounds like the dog was the alpha one in the family. You can overcome it or allow it. Some breeds will most be aggressive and very hard to combat. For instance Pit bulls, yes there is a low percentage that won’t hurt a fly but the majority will kill. All dogs will bite and should never be trusted 100%. Once the dog does show aggressive behavior it should NEVER be trusted. Dogs will bite out of fear, drive or temperament. Hounds usually are not bitters, but are a pack type dog but also has a determined pecking order in rank structure. You might say she was the only dog and what structure you talking about. Your family is the rank structure. When you let a dog become dominate over someone, it’s rank structure increases. As time goes the dog rules over most or all if allowed. They are animals, if you let them be the alpha in the house you get what the dog deems appropriate in its eyes.