Simplify the following text for a Grade 6 native English-speaking person.
Original: Thelma Catherine `` Pat '' Ryan Nixon ( March 16 , 1912 â `` June 22 , 1993 ) was the wife of Richard Nixon , 37th President of the United States , and was First Lady of the United States from 1969 to 1974 .
Simplified: Patricia Ryan Nixon ( March 16 , 1912 - June 22 , 1993 ) was the wife of Richard Nixon , the 37th President of the United States . She acted as the First Lady of the United States from 1969 to 1974 .