Timandra

The daughter of king Tyndareus and Leda, and sister of Helen of Troy, Clytemnestra, Castor and Polydeuces.

Tyndareus had been cursed by Aphrodite for not sacrificing to her, and the curse was that the king's three daughters would all be adulteresses.

Timandra was married to Echemus, son of Aeropus, who succeeded king Lycurgus of Tegea. They had a son, Augeas, and according to some sources Timandra eventually left her husband for Phyleus. This is not certain, though, but makes sense since she was cursed to commit adultery.