[Note: The following continues GRRM's series of descriptions of notable Targaryens (and Targaryen bastards) for Amoka.]
Lady Shiera was the natural daughter of King Aegon IV by the ninth and last of his mistresses, Lady Serenei of Lys, the last daughter of an ancient but impoverished line of Valyrian nobility. "Sweet Serenei," Aegon called her, but about his court she was considered cold and haughty, and some said that she was much older than the king, and preserved her beauty by the practice of dark arts. Considered by many the most lovely of Aegon's mistresses, Sweet Serenei died in childbed, bringing forth the last of the king's "Great Bastards," the daughter she named Shiera, Star of the Sea.
Shiera was born with one dark blue eye and one bright green one, but the singers said that this flaw only accentuated her loveliness. She was the greatest beauty of her age, a slender and elegant woman, slim of waist and full of breast. She had the silver-gold hair of the Targaryens, thick and curling, and wore it very long. At some points in her life it fell well below her waist, almost to the back of her knees. She had a heart-shaped face, full lips, and her mismatched eyes were strangely large and full of mischief; her rivals said she used them to melt men's hearts. Even at an early age, she was a great reader. She spoke a dozen tongues and surrounded herself with ancient scrolls. Like her mother, she was reputed to practice the dark arts. Though she never wed, she had many offers, and several lovers through the years. Duels were fought over the right to sit beside her, men killed themselves after falling from her favor, poets outdid each other writing songs about her beauty. Her most ardent admirer was her half-brother, Bloodraven, who proposed marriage to her half a hundred times. Shiera gave him her bed, but never her hand. It amused her more to make him jealous.
As to how to paint her... she was fond of ivory and lace and cloth-of-silver (but not gold, which she considered too vulgar). Her favorite piece of jewelry was a heavy silver necklace of emeralds and star sapphires, alternating.