My Sarah Elizabeth Catherine Light is the Sara, age 5, who appears in the 1850 census of Humphrey Light's household. That would lead one to expect that she was daughter of Humphrey (and niece of your Patience Hance). However, I have Sarah's death certificate and it lists here father's name as Riley Light.
Of course, the death certificate could be wrong, but since there was a 7 year old Riley in the same household in 1850, it is conceivable that both were children of (a deceased?) Riley, living with (maybe) Uncle Humphrey? But then, Humphrey disappears from the record, too.
I presume you have read the other, earlier, responses in this thread. Some very interesting information there.