KATHMANDU, May 26 (AFP) - A Nepalese pregnant mother killed her three children then poisoned herself driven to despair by poverty, police said Wednesday. "Manju Thapa, 26, who was pregnant, killed herself along with her two daughters and a son, at about noon on Monday after taking poison-tainted food," Police Superintendent Ram Chandra Khanal said. "Due to extreme poverty and in desperation, the woman killed herself and her children," Khanal said, adding police are investigating. Manju's husband, Uttam Thapa, a tuberculosis patient, was not at home when the posioning took place.  