Bill, do you have any info at all on your James and Margaret? I have a Thomas Devlin b. about 1803 in Ireland who married an Ellen Dugnon b. about 1804 in Ireland (that is from a death certificate of their son from 1921, so who knows how her name was really spelled.) I do not know if they married in Ireland or Canada.
Don't know where they were from but they went to Canada, had a few children there in the 1830s and 1840s and then came to PA in the US late 1840s.
They named a son James as well as one named Thomas. And there may have been a daughter Margaret if I can match up the family from 1850 to the family in 1860!