Simplify the following text for a Grade 3 native English-speaking person.
Original: In 1916 , American Louise A. Field cashed in on the popularity by writing books such as Peter Rabbit Goes to School or Peter Rabbit and His Ma , the illustrations of which showed him in his distinctive blue jacket .
Simplified: In 1916 , Louise A. Field became rich by writing books such as Peter Rabbit Goes to School or Peter Rabbit and His Ma .