MOUNT PLEASANT, Mich. — A 12-year-old boy stabbed his sister in the arm in an argument over a chicken pot pie, authorities said. The boy is charged as a juvenile with assault with intent to do great bodily harm less than murder and assault with a dangerous weapon, said Robert A. Holmes, senior assistant Isabella County prosecutor. The alleged attack took place Monday evening at the siblings' home in Mount Pleasant. "They were having a brother-sister argument," Officer Michael G. Covarrubias told The Saginaw News for a story Wednesday. "This is going to make them sound stupid, but they were...