A woman who plunged from the balcony of a Carnival cruise ship  near Catalina Island had been arguing with her family just moments before jumping to her death, according to a source familiar with the case. The FBI is still investigating the shocking incident, which happened early Monday morning aboard the Carnival Firenze ship. The source told The California Post that the unidentified woman jumped from her stateroom balcony and plummeted to the deck below. A woman who plunged from the balcony of a Carnival cruise ship near Catalina Island had been arguing with her family just moments before jumping to her death. Carnival Carnival spokeswoman Julie Leonardi confirmed the passenger’s death, adding that the victim was traveling with family who alerted the ship’s crew of the horrific episode. “As is customary following these kinds of incidents, law enforcement was on board while the ship was in Catalina Island on Monday to collect information,” Leonard said.…