Scottish terrior anger issues?

I have this dog her name is Dixie shes about a year now and she barks and growls at all these people especially certain type of people. She also barks at kids because when she was a puppy i had found kids that threw rocks at her i got the kids to stop but i feel she doesnt trust them. She doesnt bark at everyone its really strange. Is there anything i could do to stop her from barking and trusting kids again?