The child will learn from her parents even if you stop hitting her, you have to change your attitude towards your family, both of you. The child picks up the aggression from their family and acts accordingly, for her it's the right thing to do. Still there's time, you both have to change your attitude and overtime you will see a positive effect in her. Also simultaneously after the family environment is improved, and after she sees the non-aggressive attitude from both of you, try and talk to her and tell her what's right and what's wrong. There is still time. Nothing is permanent yet. Hope you mould her to be the best