WATERTOWN, N.Y. (AP) - A 25-year-old northern Lewis County woman has admitted causing injuries that killed her 6-month-old niece last year. The Watertown Daily Times reports that Amber Simpson pleaded guilty Wednesday to criminally negligent homicide and was sentenced to from one to three years in prison by a Jefferson County judge. Simpson told investigators she choked Rachel Wood-Main after getting frustrated while trying to quiet the child in her care in the village of Carthage. The girl had a neck and spine fractures and died Dec. 4. Simpson apologized to her younger sister, Christine Wood-Main, for her child's death. (Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)