2015-11-16 15:30:13 UTC
Mottel is Fruma Sarah's great-grandchild.
Tzeitel is also Fruma Sarah's great-grandchild. We know this because when Tevye finishes telling Golde about the dream, Golde says, If my grandmother Tzeitel, may she rest in peace,took the trouble to come from the other world to tell us about the tailor all I can say is that it's for the best. It couldn't possibly be any better."
Individuals who share a great-parent are 2nd cousins. That is what Mottel and Tzeitel are to each other. Which would not be at all surprising in shtetl circumstances.
Mottel is a Yiddish nickname for the name Mordechai that appears in the Scroll of Esther.