Mary Heaphy born 1757, eldest daughter of Tottenham Heaphy and Alice Heaphy, both actors.
Mary, a protestant, married on 1 Oct 1774 to John O'Keeffe, a Catholic. [1]
"A successful actress in Ireland, and later Britain, Mary O'Keeffe made her debut as Juliet in ‘Romeo and Juliet’ at Smock Alley on 18 March 1775."
Mary Heaphy later married George Graham, a Scottish actor, for she felt that, as a Protestant, her first union with a Catholic was "not sufficiently binding to prevent a subsequent marriage."[2]
She passed away in 1813.
Information from "John O Keeffe, Dramatist" by Patricia O'Keeffe. http://okeeffeclans.com/johnokeeffedramatist.html