Kitty Murphy is an eleven-year-old, high-spirited young girl growing up in 1950s Ireland. When her elder sister leaves the family farm to attend school, Kitty must step into her shoes and become the ‘Big Girl’ – i.e., rear her siblings, manage chores, etc. Kitty struggles to satisfy all the expectations placed on her and her childhood innocence suffers as a result. Throughout the year, awful things happen to the Murphys – their father contracts cancer, their mother suffers a stillbirth, and their eldest sister goes missing after a pregnancy. With all this misery, Kitty must find strength in herself to become the ‘Big Girl’ she desperately yearns to be.