what does beatrice think happend to hero
Beatrice believes Hero has been "belied" (BEATRICE:O, on my soul, my cousin is belied!). The reason she feels this way is because she has been her "bedfellow" for the past year (with the exception of the night before Hero's wedding). Through an in-depth look at characterization, Beatrice can vow for her cousin's chastity because she has shared her bed (which was common for Renaissance women family members) for the last year. She knows her cousin's true character and believes that Hero has been slandered. Beatrice's feelings about Hero can also be found later in Act IV when Beatrice is speaking with Benedick; she asks Benedick to challenge Claudio as a man (meaning, with a dual) since she cannot as a woman. It was common for men to challenge other men to duals to secure the honor of a subject or person.