Grantland has an article about the 25th year anniversary of "When Harry Met Sally...", talks about the potential Jewishness of various characters, and throws the following wonderful part:
Even the excellent website Jew or Not Jew is stumped about Rachel, although it expresses a firm conviction that Seinfeld’s Elaine is not Jewish, which would make her the only frizzy-haired brunette Upper West Sider named Elaine in the history of Manhattan Island not to be.
Nope... Elaine is CLEARLY not Jewish. Sorry, Grantland!
Jerry (reading): Jewish singles night?
Kramer: I expect you both to be there.
Elaine: I'm not Jewish.
Kramer: Well neither am I.