AITA for telling my sister she can stay with me but her dog can't come?

My sister is trying to leave her abusive husband. She doesn't want to leave her dog who her husband has also abused. If her dog was well behaved and not aggressive then sure. I would let it stay. But because the dog also has trauma that dog is extremely violent and my 14 year old son who is on the spectrum already has a phobia of dogs. He also has an Emotional support cat. And that dog would 100% attack his cat. I want to help my sister but I also can't disturb my child's home to help her. She has the option to go to a shelter that takes pets but she doesn't want to go to a shelter and they could also have a problem with the dog being aggressive. The dog also isn't trained at all. She never trained it which is her fault. It sucks because dogs are not bad. They have bad owners but again I cannot disturb my kids home and put us all in danger to help her. She can come. Her dog just can't. There are places she can surrender the dog in our city that will rehabilitate the dog but she doesn't want to be separated from her dog?