'Supernatural' actress Nicki Aycox has passed away aged 47, her sister-in-law Susan Raab Ceklosky confirmed in a Facebook post. "My beautiful, smart, fierce, incredibly talented, and loving sister-in-law...passed away yesterday...She was definitely a fighter," Susan wrote. While she didn't disclose the cause of her death, Nicki revealed last year in March that she was diagnosed with leukemia.