It looks like my husband does not descend from this line (it would be his, not mine). My question was speculative. The Grant line from which he descends were elders in the Kirk of Scotland (St. Andrew's, Williamstown), so the R.C. heritage pretty much voids that connection unless there was a conversion before about 1800.
I'm having a huge problem tracing this line back to Scotland. When did they come over? Before or after the Revolution? (Donald) Alexander Grant (1755-1840) received a Crown Grant in 1803 in 2nd SSRR, but I have not been able to learn on what basis it was given, which would go a long way toward learning when the family emigrated. There's a tombstone in St. Andrew's graveyard that identifies his father as Alexander Grant (1733-1791) married to Marjory Grant. The trail ends there... so far.