She was a domineering woman who cowed her son into submission and often came between him and Sally - she'd even go on dates with them! (And to make matters worse, she'd sit between them.)
Mrs. Glimsher's husband died many years before, something which he must have seen in his final moments as truly a "blessed release". And so Mrs. Glimsher must have needed a job to make enough money to raise her Mama's Boy.
A woman so overwhelmingly strong-willed would easily be hired for a supervisory position in the workforce.
And I think we got the chance to see Mrs. Glimsher in action.......