It is hard not to sympathize with Hermione, who is falsely accused by her husband of having an affair with Polixenes.
First, it is clear to the audience that her husband's jealousy is irrational. As Hermione herself notes, she is simply doing what her husband commanded in being hospitable to her guest. As she puts it when on trial:
With whom I am accused, I do confess
I loved him as in honour he required,
With such a kind of love as might become
A lady like me, with a love even such,
So and no other, as yourself commanded . . .
Third, she shows a great deal of poise and self-possession throughout her ordeal. Frustratingly, too, her husband holds all the power and has already made up his mind as to her guilt. No matter what she says, he twists it into words of guilt. He is both judge and jury, and he is determined not to believe in her innocence.
Anyone can imagine how frustrating it is to be falsely accused, especially when the accuser is more powerful. Further, Hermione is so loving a mother that the death of her son causes her, we are told, to die of grief. We feel for Hermione because of all she suffers unjustly and because of the grace she exhibits under pressure.