Who is Mashah Smolinsky from Bread Givers and what is their importance?

Mashah is Sara's sister. When we first meet her, she has just spent ten cents for flowers to put on her hat. Unfortunately, she does so when the family isn't even sure they can pay their rent. Over the course of the novel, Mashah falls in love with a pianist, but the boy's father objects to the match. When the young man asks Mashah for another chance, Reb insists she stop seeing the young man and arranges another marriage. Sadly, Reb believed the man's claims that he was a diamond dealer, when in reality, he was only a clerk. Masha spent her life living in poverty.