Roger McGowan and Sarah Flynn family of Ballymote

My ancestor, Eliza McGowan, and her sister, Jane, both married in Lynchburg, Virginia, USA. Their marriage records in Virginia show they are both the daughters of Roger McGowan and Sarah Flynn of County Sligo. Eliza married Mike McNally of County Down in 1854 in Lynchburg. Jane McGowan married Joseph Bragassa of Palermo, Italy in 1861 in Lynchburg. From these and later records it appears that Eliza was born about 1829 and Jane was born about 1838. It appears they have a younger brother James McGowan, also born about 1838. He lived in St Louis, Missouri with Eliza and her husband in 1860 and was a baker. Jane's son identified Ballymote, Ireland as his mother's birthplace. 

Based on these birthdates, I would assume that Roger McGowan and Sarah Flynn married before 1828 and were living in Ballymote in 1838.

The Tithe Applotment Books show a Roger McGowan in Kilmorgan Parish, Drumfin Townland, County Sligo in 1833 who may be my ancestor.

A Sarah McGowan, age 69 (b abt 1797) died in County Sligo in 1866

The Sligo Death records Index shows a Roger Gowan, age 70 (b abt 1753) was buried in 1823.

I have not been able to identify the family on any passenger lists. A Roger McGowan,petitioned for naturalization in Philadephia, PA on 3 Jan 1840. He was 46 so would have been born about 1798, but I do not know if this is the one I'm searching for.

Since they are Catholic, I checked the LDS Baptisms & Marriages Microfilm (#926016) which contained Catholic marriages for  Diocese Achonry, Parish Emlefad & Killmorgan from 12 Aug 1824 – 7 Jan 1866. There were a number of McGowans and Flynn's listed but Roger and Sarah did not appear as witnesses or spouses. If they married in Ballymote, I must assume that it was before 12 Aug 1824.

This film also had Baptism Records for the Parish beginning in 1856. There is a Dominick McGowan baptised May 1868 listed. His parents names are not listed, but Drumfin is listed as the parent's town. I am curious whether he is related.

Any knowledge of these McGowans or clues where I might find further records would be greatly appreciated.

Terri S