Only 14 people around the world have bilateral macrostomia. The parents did not know about their daughter's condition because it did not register in the scans or ultrasound.
‘Permanent smile’ baby born in Australia with ‘bilateral microstomia’, know more about the rare condition - According to Wikipedia, macrostomia is an extremely rare condition that affects only one in every 1,50,000 to 3,00,000 live births on an average.