Who is Emmy Oppenstein from The Finkler Question and what is their importance?

Emmy Oppenstein is an elegant, elderly Jewish woman who had been friends with Libor fifty years ago. She contacts Libor for help in alerting the media after her grandson is blinded in an anti-Semitic attack. Emmy had also been Libor's lover long ago, though he does not remember her. She visits Libor's graveside after his funeral where she meets Sam and Julian and expresses her concern that her request for help was overwhelming and contributed to Libor's suicide.