I thank Rubypitbull for the kind words. Ruby seems to have more experience with formerly abused pit bulls than I do. Beth is good too. I certainly agree on the spaying. In addition to the ''honeymoon'' period, she is still maturing which can lead to problems as she decides she is a big girl now and ready to claim her place in the pack.
I think many people make the mistake of expecting all members of a breed to be alike. You may or may not be able to salvage her. The first step is a vet check. If a physical problem has left her out of sorts, nobody can train that away.
The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at
Raising Your Dog with the Monks of New Skete For more on being top dog, see
Establishing and Keeping Alpha Position That site also has a good page on dogs and children.