Simplify the following text for a Grade 6 native English-speaking person.
Original: Jane Irwin Harrison ( Mercersburg , Franklin , Pennsylvania , July 23 , 1804 -- May 11 , 1846 ) , who married William Henry Harrison Jr , was the daughter-in-law of William Henry Harrison , ninth President of the United States .
Simplified: She was married to William Henry Harrison Jr. . William was the son of William Henry Harrison , ninth President of the United States .