Simplify the following text for a Grade 6 native English-speaking person.
Original: Patricia `` Tricia '' Nixon Cox was born on February 21 , 1946 in Whittier , California . She is the daughter of former US president Richard Nixon and Pat Nixon .
Simplified: Patricia `` Tricia '' Nixon Cox ( born February 21 , 1946 ) is the elder daughter of the 37th U.S. President Richard M. Nixon and First Lady Pat Nixon , and sister to Julie Nixon Eisenhower .