Hero is presented as a very sweet, loving, modest, and virtuous maiden.
We first learn of Hero's modesty and sweetness when we witness Claudio's reaction to meeting her. Claudio describes Hero as "the sweetest lady that [he] ever looked on" (I.i.160). He also likens her beauty to a precious jewel, as we see in his line, "Can the world buy such a jewel?" (155).
Hero, herself, also confirms her own modesty when she is asked by the other characters to work with them in tricking Beatrice and Benedick into falling in love. Her reply is that she would do anything a modest, virtuous maiden would do to trick her cousin into getting a husband, as we see in her line, "I will do any modest office, my lord, to help my cousin to a good husband" (II.i.330). We see her modesty again the night before her wedding day when she is getting her bridal attire set out with Margaret. After Hero mentions that she is feeling "heavy" at heart, she chastises Margaret for making an immodest sexual joke, saying that Hero's heart will soon "be heavier by the weight of a man" (III.iv.22-24).
We again see Hero's modest gentle nature when she is wrongfully publicly shamed by Claudio before the altar. When he first begins hurtling accusations at her, she does nothing more than blush like a maiden. She does not even reciprocate Claudio's harshness by speaking harshly back at him. All she does is try to defend herself and ask Claudio if he has lost his sanity, as we see in her line, "Is my lord well that he doth speak so wide?" (IV.i.59). Also, in accordance with her sweet, gentle nature, she faints from the shock and horror of the event.
Finally, we also see Hero's sweet, loving, and virtuous nature portrayed when we see her forgive Claudio enough to carry through with a second wedding. Through her forgiveness and her faked death, she proclaims herself to be born anew, as we see in her lines:
And when I lived I was your other wife; ...
And when you loved you were my other husband.
One Hero died defiled; but I do live,
And surely as I live, I am a maid. (V.iv.61-66)
The things Hero says and does, other characters' responses toward her, and her responses toward other characters, including her forgiveness, help to show us that Hero has been presented as a very sweet, loving, virtuous, and modest character.