Nancy Walker starts as Ida Morganstern, Rhoda's VERY Jewish and smothering mother. She's so difficult for Rhoda to deal with that she has simply refused to answer her door to her. So, Ida sits in the hallway...and she ends up making a lot of noise and Mary finds her. Mary, being a ridiculously nice person, takes her in and tries to help. Not surprisingly, it ends up being MUCH tougher than just letting Ida stay for the night.
While Nancy Walker never achieved much stardom as a contract player for MGM during her younger days and certainly should NOT have tried her hand at directing (she directed the Village People in the god-awful "Can't Stop the Music"), she was absolutely perfect playing a smothering Jewish mom. She only appeared on "The Mary Tyler Moore Show" a few times...but they were all wonderful appearances.
Overall, a very funny and memorable episode. While I don't think it's the best episode of season one, it's one of the better ones...and it received an Emmy for Outstanding Writing.