A Texas mom has been charged with capital murder after her two young children were found dead inside a car that had been set on fire, according to authorities.  San Antonio police discovered the kids – believed to be 5 and 7 – after a person walking their dog around 5 a.m. Friday called 911 to report a vehicle on fire in a parking lot behind a warehouse.  That witness later identified the children’s mother, Marlene Vidal, as being near the white Hyundai as it was engulfed in flames, authorities said during a news conference Friday .  Vidal, 34, later told cops that she was the mother of the two deceased children — and “that she was the one that we would be looking for,” said San Antonio Police Assistant Chief Jesse Salame.  The bodies of two children who are believed to be 5 and 7 were discovered inside the torched white Hyundai, according to San Antonio authorities.…