Who is Fina-Kajsa from Unto a Good Land a Novel and what is their importance?

Fina-Kajsa traveled from Sweden with her husband in the hopes of settling in Minnesota. Her husband died on the sea voyage, and she remained a part of the group. Her son, Anders Mansson, settled in America several years before her voyage, and she believes that he made an incredibly prosperous life for himself. Sadly, when she arrived in America, she learned that it wasn't true.