Welcome to the family. Advise about adding another one? Hmmm I don't think you want advise from a mom of 2 spoiled bullies and a spoiled "off-breed" LOL
I love having two, between the two of them, there is never a need to warm my lap with a blanket or turn the TV on to drown out the quiet of the night.
When I got Bella, I was told multiple females may not get along. All three of my dogs are females. They have their moments, but for the most part they aren't any different than Skin-kid sisters. I brought a rescue dog in for a couple days, a male, they did great with him as well.
You can check out our adoption page, there are a lot of bullies out there for adoption if that is what you are looking for. If you want a puppy, research the breeder real well. I couldn't stress that enough.
Again, welcome, this is a great place for bully owners and you will get addicted soon. Just a warning.