AA 9781 then AA 1533 at Philadelphia
New York LaGuardia → Philadelphia → Houston
Timetable, Philadelphia time
06:00AA 9781 from New York LaGuardia at the gate
18:35AA 1533 to Houston leaves the gate
12 h 35 apart on the timetable
AA 1533 leaves 12 h 35 after AA 9781 arrives on the timetable: more than half a day, so not a connection we count.