She really was amazing! She was only 33 years old when this was filmed. She gained 30 pounds to play a mid-40s ball-breaking drunk.
This is from the blog, Signature Roles:
Her performance was and is still one of the most modern pieces of film acting ever. Her Martha is a ruthless, fierce, thunderbolt of rage and unacknowledged grief. She enters hard, like a wheel barrel of bricks being dumped on your front porch, and never let's up - until the last moment. Her hard thrust and power is an equal match to the amazing film-making.
