A 25-year-old woman from the Crow Indian Reservation is to be sentenced in federal court today for killing her 3-year-old daughter by throwing her out of a fast-moving vehicle. Mary Agnes Leider pleaded guilty to second-degree murder and could face more than two decades in prison. Authorities say Leider was riding with her daughter in her lap in a pickup driven by her brother after a night of heavy drinking last December when she opened her door and threw the girl into the road for reasons that remain unclear.