Lynn-
I have several Cowley's that came from the Isle of Man in England. My Great Grandmother was LaRu Estella Cowley. Her father was James Heap Cowley. His father was James Cowley who married Mary Heap. He was also married to a woman named Isabella Ann Cain. I think he was the "brother" from your ancestry who joined the Church of Jesus Christ of Latter-day Saints and crossed the United States plains with Brigham Young.
His (James')father was John Cowley married to Ann Gorree. And John's father was Robert Cowley, married to Catherine Quine. According to my records, James had five brothers and one sister: Thomas, William, John, Robert, Charles and Catherine.
Does any of this ring a bell?
Ann Marie Johnstone