Scanlan/Barnhill Families

I'm hoping to trace my lineage on both the Scanlan and Barnhill sides. My maternal grandfather was a Scanlan.

I've found records from "Ireland Births and Baptisms, 1620-1881", noting Andrew Scanlan and Martha or Margaret Barnhill had 6 children between 1825 and 1838, which was confirmed by the Camus parish registry (attached as 'scale'). http://cotyroneireland.com/births/CamusBirthsS.html

I also believe they immigrated in 1947 from the "Pennsylvania, Philadelphia Passenger Lists Index, 1800-1906". Martha is noted as a spinster, so I am curious is Andrew was married to a Margaret Barnhill who died prior to their leaving Ireland and Martha was his sister. I would be grateful for any information.

Thanks in advance.