Who is Mrs. Hannagan from Wake and what is their importance?

Mrs. Hannagan is Janie's mother. Mrs. Hannagan is an alcoholic. She collects a welfare check that she uses to pay for rent and her liquor. Mrs. Hannagan is always passing out on the couch or in her room. She also leaves her empty liquor bottles all over the house, never cleans up and doesn't even go to the store to make sure that there is food in the house for Janie. Mrs. Hannagan seems oblivious to Janie and what is going on in the world. She only cares about drinking.