Complex sentence: Kathleen O'Regan (11 November 1903--10 December 1970) was an Irish actress, best-remembered for her performances in the first London performances of "Juno and the Paycock" and "The Plough and the Stars".
Split into simpler sentences: Kathleen O'Regan (11 November 1903--10 December 1970) was an Irish actress. She is remembered for her performances in the first London performances of "Juno and the Paycock" and "The Plough and the Stars".