In 'Much Ado About Nothing', Beatrice's cousin is Hero. Hero is the daughter of Leonato, the governor of Messina, and she lives with Leonato and Beatrice in the play's Sicilian setting.
Hero becomes romantically involved with Claudio, a young soldier who arrives in Messina with Don Pedro and Benedick. Their relationship is nearly destroyed when Don John stages deceptive evidence suggesting that Hero has been unfaithful. Claudio denounces her publicly at their wedding, and a friar proposes that Hero pretend to have died until the truth emerges.
Beatrice is also central to the play's second romance. She and Benedick wage a witty 'merry war' before their friends trick each of them into believing the other is in love. Beatrice fiercely defends Hero and asks Benedick to challenge Claudio after Hero's humiliation.
Leonato is Hero's father, not her cousin. Margaret and Ursula are Hero's attendants, while Lucetta and Portia belong to other Shakespeare plays. Hero is ultimately proved innocent and reunited with Claudio at the conclusion.