Simplify the following text for a Grade 9 native English-speaking person.
Original: Jelena KaraÄ ` orÄ ` eviÄ or Princess Helen of Serbia ( 4 November 1884 â `` 16 October 1962 ) was the daughter of King Peter I of Yugoslavia and his wife Princess Zorka of Montenegro .
Simplified: Princess Helen of Serbia ( 4 November 1884 -- 16 October 1962 ) was the daughter of King Peter I of Yugoslavia and his wife Princess Zorka of Montenegro .