A 7-year-old girl died Sunday night in Bergen County after she was found at the bottom of a swimming pool that had been rented for a family party, authorities said. Police responded about 6 p.m. to a home on Westervelt Place in Teaneck for a report of a missing child, according to township police Chief Glenn M. O’Reilly. The child “was located at the bottom of an in-ground pool. CPR was initiated and she was transported to Holy Name Medical Center,” O’Reilly said. The girl was pronounced dead at the hospital at 7:22 p.m., the chief said. O’Reilly said the drowning occurred at a backyard pool t…