This is such an old thread, but I do wish to point out that she probably wasn't that great of a worker. The scene of her on the floor cleaning the brown residue on the floor showed this. She was out of breath and taking forever to clean it up. Much of the work she did was pointless and effortless, and she made it look like she was building a stone house.
She was just depressed. She was just a typical person who thinks she has the worst life in the world, but in reality, her life was not that bad. She victimized herself, just as her grandson did. This is the same woman that said her grandson wasn't a bad guy for raping and murdering a woman. She wasn't a good worker and she wasn't a good person. Mikey was the voice of reason in that regard.