Tamar was the daughter of King David and Maacah, who was the daughter of Talmai, king of Geshur. Absalom was her brother and Amnon their half-brother. The Bible does not speak of Tamar's early life; however, in 2 Samuel 13, she is wearing a "richly ornamental robe", "for this is how the virgin daughters of the king were clothed in earlier times."
–Wikipedia