Thank you for the response but I don't think that Marianne Kanter is the girl with the ring. There are other uncredited roles in "The Pawnbroker", in particular the opening family scenes. I think Marianne Kanter may have played one of those roles.
In "The Pawnbroker", who played the pregnant girl trying to pawn her ring? She looks like a very young Leslie Ann Warren but is not credited. Note that Morgan Freeman also appears in this film but is also uncredited. https://www.youtube.com/watch?v=XSUU-_0cWn4