Forgive my ignorance on DNA testing, but do you have to be a male with the surname Cork(h)I'll for this test to be useful. My grandmother was Juilia Corkhill, daughter of USA born Robert Corkhill, the son of Manchester born Thomas Corkhill, who was the son of Douglas IOM born William Corkill. He was born there in 1801 and left the Isle in the 1820s.