Three Australian teenagers have been praised after rescuing a heavily pregnant woman and her three children during a unit fire in Sydney's west, the New South Wales Police said on Wednesday. The girls, aged 12, 13 and 15, were walking along Popendetta Road, Blackett at around 5 p.m. (local time) on Tuesday when they noticed a unit was on fire. Two of the girls ran to the woman's unit to help her and her three children out of the unit safely while the other girl called emergency services, police said. The blaze was later extinguished by fire crews and the pregnant woman checked at the scene by ambulance paramedics. Another woman who was found in the back yard of the premises was taken to Blacktown Hospital for assessment, police said. The three girls are expected to be nominated for an award by police in recognition of their bravery. Police are investigating the cause of the fire.