Elaena Targaryen was the youngest daughter of Aegon III Dragonbane.
According to non-canon sources, she was one of the infamous sisters locked in the Maidenvault by Baleor I at the age of 11. She was unhappy with her brother over that and cut off her famous braid in protest. She had three husbands during her life, however her the great love of her life was her cousin Alyn Velyaron, with whom she had two children Jon and Jeyne Waters.
She was known as shrewd and intelligent, to the point that even though her husband sat on the King`s Small Council as Master of the Coin, it was widely known that she was the one performing the duties.
References and Sources
- Three Maidens in the Tower (June 27, 2006)http://www.westeros.org/Citadel/SSM/Category/C91/