Here's a snatch of one that might fit the bill - it's called Ballad of a Working Mother, by Marilyn Major:

My kids were only babies when their daddy went away.
So I hung up my apron and went out to work for pay.
They put me on the night shift working at a big machine.
And that was the last of normal life my kids and I have seen.

It's from "Carry it On" by Pete Seeger and Bob Reiser, which has the rest of the words and the tune as well - together with lots of other songs that might suit, from further back, like Woody Guthrie's Deportees - and also "Nine to Five" as a more recent example of a song about people getting a hard time at work.