A Florida judge has accepted a plea agreement that would spare a German grandmother from a potential death sentence.

Marianne Bordt, 73, was charged with first-degree murder and aggravated child abuse. She allegedly drowned her 5-year-old grandson, Camden Hiers of suburban Atlanta, in the bathtub of a beach house in January 2010.

Circuit Judge Angela Dempsey accepted the proposal for a reduction in charges and 21.5 year prison term at a hearing Monday in Apalachicola.

Camden died while Bordt and her husband were vacationing with their grandson on St. George Island in the Florida Panhandle.

Her lawyers were preparing an insanity defense for an October trial. It included a claim she suffered mental problems in part due to a World War II Soviet bombing raid.