MEMPHIS, Tenn. -- A family is asking the public for help after her teenage daughter went missing nearly a week ago. Cheyenne Poole, 17, was last seen on January 14 in the 1800 block of Person Ave. Cheyenne Poole. (MPD) According to police, Poole left the grandmother's home without permission and refuses to return. She left the area with an unknown person in a gray SUV. Poole has stopped communicating with her family and they are worried for her safety.