What does Mary remember about times when her mother was having "a day" (133)?

Mary remembers times when her mother was having a day. The first time was when Mary was three or four. Her mother was scrubbing the floor removing dirt that was not there. She told Mary to help. When Mary did not see anything, her mother slapped her. Another time when Mary was seven her mother stayed in bed for days. The food in the fridge spoiled. The lights were shut off.