Who is Hermione in The Winter's Tale?

Hermione is Queen of Sicily, wife to Leontes, and mother to Mamillius and Perdita. She is a gracious and friendly host who tries to convince Polixenes, Leontes’s best friend, to extend his stay in Sicily. In fact, she does not easily take no for an answer. Hermione declares, “Verily, / You shall not go: a lady's 'Verily' 's / As potent as a lord's,” and says she will be forced to keep Polixenes “as a prisoner.” Hermione and Polixenes enjoy this banter, and, while Leontes also seems to, his thoughts quickly turn to jealousy.
Almost immediately, Leontes plots the demise of his closest friend and the arrest of his wife. Polixenes escapes, but Hermione, pregnant with the unborn Perdita, is thrown in prison. Leontes is convinced Polixenes is the baby’s father, and he refuses to let their son Mamillius see Hermione.
The queen’s reputation for virtue is widely known, and everyone in the king’s circle attempts to convince him of her innocence. Paulina is especially outspoken, calling Hermione “a gracious innocent soul, / More free than he [Leontes] is jealous,” and hurling numerous insults at the king, on pain of death. Hermione has the child, whom Leontes exiles to the wilderness of Bohemia. Mamillius dies, Hermione collapses and is reported to die, and Leontes, all too late, comes to his senses.
Leontes grieves for over a decade. Unbeknownst to him, Hermione lives in hiding and Perdita was discovered and raised by two farmers. Eventually, Perdita and Polixenes reunite with Leontes, and Paulina reveals a “statue” of Hermione that turns out to be Hermione herself. It is a poignant ending and a marvelous reconciliation, although it cannot fully erase the lost years and lives of the past.
http://shakespeare.mit.edu/winters_tale/full.html