Hermione

Hermione is the firstborn child of Helen and Menelaus of Sparta.

Betrothal and Marriage
Hermione was first betrothed by her grandfather, Tyndareus to her cousin Orestes. During the Trojan War, Menelaus betrothed her to Neoptolemus, or otherwise known as Pyrrhus, son of Achilles.

Ten years after the War Hermione married Neoptolemus but while Neoptolemus was away at war. Hermione ran off with her cousin, Orestes. They were married and Hermione gave birth to his heir, Tisamenus.