Ramona Allmond's daughter and grandson were arrested Sunday on suspicion of embezzlement, elder abuse and disposing of a body without a permit.
Allmond, 84, likely died of natural causes, though investigators were still trying to determine the exact cause of death, said Tehama County sheriff's Capt. Paul Hosler.
Allmond's daughter, Kathleen Allmond, 50, and Allmond's grandson, Tony Ray, 30, told investigators their relative died in December. They left her body on her bedroom floor for a week before cremating the remains in their backyard fire pit, Hosler said.
Investigators said the two kept collecting Allmond's monthly retirement checks, amounting to more than $25,000. Sheriff's Detective Richard Knox said they may have been trying to honor Allmond's desire to die at home and be cremated.
The two were arrested after Allmond's son grew suspicious about her whereabouts.
Both were in jail in lieu of bail, with arraignment scheduled for Thursday. The sheriff's department said they do not yet have attorneys.