It's definitely not the end of the world!!!! And you are not a bad bully mummy at all.
IF she is deaf or partially deaf then it's something she has clearly adapted to.
For your own piece of mind I would find out for sure. You can go on the Internet and learn hand signals that mean certain things. They are fairly universal. We had a bully come into rescue who was totally deaf. Her name was Bubbles, and she was a total joy!!!