Keisha Nash Whitaker, the ex-wife of Oscar winner Forest Whitaker, has died. The model, actress and former host of TLC’s “What Are You Wearing?” was 51 years old. The former couple’s 25-year-old daughter, True, shared the tragic news on social media Thursday, but did not provide a cause of death. “Goodbye mommy. I love you 4ever and beyond. The most beautiful woman in the world,” she wrote in her Instagram Story. “Thank you for teaching me every single thing I know. I’ll see you in my dreams and I’ll feel you in my heart.” True also shared several archival photos of her mom set to the tunes of…