A northwest Harris County stable owner was found stabbed to death inside her home early Sunday, and a 16-year-old hired hand who lives in a trailer at the stables confessed to killing the woman during an argument, police said. He was charged with murder and transferred to the Harris County Juvenile Detention Center, detectives said. An employee and her boyfriend found the body of the woman, 50, about 7:45 a.m. inside her home at the Oaks of Kendalwood stables at 14003 FM 529. Her name was withheld pending notification of next of kin, Harris County sheriff's detectives said.