I had a Pit/Chow mix, he the best dog I have ever had, he was stray that I took in. I also had a full blood pit show up, starving to death, so I took her in. She turned on my son, my husband and my BIL, and I had her put down. Maybe it was something from her background, I do not know. She never turned on me, so I don't know if it was just something about male or what? Maybe a male abused her, but I couldn't be positive. But, JMO any dog can turn on you no matter the breed.
If mom isn't comfortable with a pit mix, then look around, there are many dogs that need good homes.