I'm thinking of keeping me and my family away from my mum
Why do you want to keep your family from your mother?
I've had so many terrible experiences with her that it's just not worth the risk.
Maybe you should talk to her and work things out. She can't be all bad you need to work on it and not just cut her out of your life.
I don't want to put myself through the pain.
I understand your pain, but trying to keep your family away from one another can be also painful in that you lose contact with those that you love. If you feel that your mom is a bad influence then maybe it is a good idea to sit down and discuss this with her to try and work things out. Try going to see your mom alone first to gauge how she is doing and see if you can work with her from there.