Who is Shprintze from Tevye the Dairyman and the Railroad Stories and what is their importance?

Shprintze is the daughter of Tevye who has the most unhappy fate of all. She falls in love with the rich young Jew Ahronchik who is totally dependent on his mother. When Ahronchik's family intervenes to break up the proposed marriage, Shprintze ends up committing suicide.