Who is Ulrika from The Last Letter Home and what is their importance?

Ulrika is Kristina's friend. She is married to Baptist Pastor Jackson, though she was a prostitute while living in Sweden's Ljuder parish. After convincing Kristina to go to the doctor, Ulrika accompanies her and explains the situation to Karl when they return from the doctor's office. Several years after Kristina's death, Ulrika chastizes Karl for being responsible for his wife's death. Ulrika later donates a bridal crown to the church in Ljuder parish, as a vindication of herself and the life she was not permitted to have in Sweden.