A woman was shot and killed Thursday inside a home in South Shore.The 43-year-old was inside a residence about 4 p.m. in the 6800 block of South Cornell Avenue when a 17-year-old boy approached her and fired shots, Chicago police said.The woman suffered four gunshot wounds to the head and was taken to the University of Chicago Medical Center, where she was pronounced dead, police said.A firearm was found at the scene, police said.No arrests were reported.