How do I get visitation of my step sister

[cmdsj]

My father and his evil wife of 14 years are getting a divorce. My soon to be former step mom is now using her 14 year old daughter against my father. Eventhough my father is not my step sister biological father, he and my step sister have an incredible bond. This upsets my stepmom since after 1 month of being separated, she already has a new boyfriend and says she wants to move on with her life. My step sister prefers my dad over her mother because her mother really only cares about herself. My step mother and dad are constantly getting into arguments and because of that she trys to keep my step sister from seeing me. Is there any way I can get visitation rights of my step sister. Are their any laws about that in the state of New Jersey?

[StillLoveHer]

Did your dad adopt her? If so then he can get visitation.