The brother of Apassara Chobthonglang, 53, summoned police in Chakkarat district to the house at 6.30am after finding her dead in bed with a large knife wound across the face and a cut on one arm.
A doctor estimated she’d been dead for about two hours.
The brother, Suchart Chobthonglan, who lives nearby, said his nine-year-old daughter woke him to report that her aunt was unwell and bleeding.
Apassara lived with her niece. Her husband works in Bangkok.
Police suspect a burglar climbed in through a window and woke the victim, though he apparently fled without stealing anything.