It's from a little-known, 1959 musical, Juno, based on the famous Sean O'Casey play, Juno and the Paycock (Irish dialect for "Peacock.") The score was written by Marc Blitzstein, who's best-known for his adaptation of The Threepenny Opera by Kurt Weill and Bertolt Brecht (which, in turn, is most famous for the song, "Mack the Knife"). Blitzstein also wrote the musical, The Cradle Will Rock, which was the subject of Tim Robbins's film, based on an Orson Welles screenplay. That's the infamous pro-union musical that was shut down by the Works Progress Administration in 1937 and got staged instead by the actors buying tickets and standing up in the audience, while Blitzstein himself played the piano onstage. (The musical wasn't allowed to be performed, but a piano concert was all right.)
Juno had an impressive pedigree. It was directed by the acclaimed actor, José Ferrer. The book was by Joseph Stein, who would go on in five years to write Fiddler on the Roof. And the choreography was from Agnes De Mille. But it only ran for 16 performances. (The story was a bit dark for the time, taking place during the Irish Rebellion, about the put-upon matriarch of a family with a drunken husband. However, musicals were beginning to get more serious, witness that year's West Side Story.) The score isn't the most toe-tapping accessible, but it did get a cast album, despite the extremely short run.
Shirley Booth is probably best-remembered for starring in the sitcom, Hazel, which won her two Emmy Awards playing the housemaid, though she also won a Tony Award and later an Oscar for starring in the powerful drama, Come Back, Little Sheba. She wasn't a great singer, but she stole the stage musical version of A Tree Grows in Brooklyn, in a supporting role. (It's later been suggested that this was, in part, the reason for that show's short run. She was so wonderful in the musical that it changed the focus of the show, and the balance of the tender story was off.) Later, she was in another flop musical, playing the Mother Superior in a stage version of Lilies of the Field.
Which brings us back to Mothers Day and Juno. (Hey, I knew I'd get here eventually.) This is the wonderful and unknown number that Shirley Booth sings as that put-upon mother. "The Song of the Ma." It's an achingly lovely song, with an even better performance. The Irish brogue is a little thick, but stick with it. It's worth it.