A woman has been arrested for allegedly strangling her eight-year-old stepdaughter to death, setting the body on fire and then stuffing the charred remains in a gunny bag in Bihar's Buxar district, police said on Sunday. The charred body of the victim, identified as Aanchal Kumari, was found stuffed in a gunny bag concealed in a wooden box in her house in Naya Bhojpur area.