It is a shame that you feel you have to defend your dog every time you go out with her. My sister has a staffy, 4 children and can't remember how many grandchildren and the only danger they are in is being licked to death. It is peoples ignorance that causes the problems and unfortunately it seems once their mind is made up it is very difficult to convince them otherwise.

My advice is - just smile at them and carry on with your walk. If they have a problem, that's their look out.