Sheila Jackson, played by the incredible Joan Cusack, is a beloved, complex character in the US version of Shameless, known for her crippling agoraphobia (fear of leaving home) and her endearing, chaotic relationship with Frank Gallagher, becoming his wife and a quirky, sweet, yet sometimes exasperating mother figure to the Gallagher clan, offering a much-needed touch of warmth and stability amidst the South Side chaos before her touching departure.