Well yes, kids generally tell a story that fits what they want adults to hear. Additionally, it appears this is another chained dog. And an adult dog adopted a year ago. Don’t know if the dog was neutered, etc. Not much info to go on. I tell you, I am not opposed to shelter dogs, but when you adopt an adult dog of unknown origins, and unknown parentage, you had be very sure you know what you’re doing and the fact that you would chain it in the yard and allow your children around it unsupervised suggests to me that you don’t meet the criteria of responsible adult. I’m just saying.
Having said that. Poor little girl, and brave big brother.
Adopting a grown dog is always a risk. I have Great Danes which I raised from pups. They are extremely gentle with people and other dogs. However I know of two adopted danes that killed small dogs in their new homes. I’ll stick to raising them from pups even though I would love to help homeless dogs.