Was my cousin's punishment fair?

She's currently 11 years old and has been acting out ever since her mother got married two years ago.
Yesterday she argued with her stepfather, squared up to him like a guy and spat in his face, calling him names. Her mother grounded her, confiscated her cell and canceled her b-day (it lands on Jan 8th). She's hurt that she won't have a b-day cake, can't communicate with her friends nor visit a couple friends. I think it's fair but she thinks her punishment is unfair. What do you think?
Was my cousin's punishment fair?
Add Opinion