When Anna Bianchis grandchild asked, "Nanny, you do know Im a girl don't you?", Anna recognised this as a pivotal moment in their relationship. She also understood that to fully support her grandchild, who had been declared a boy at birth, she needed to examine her own attitudes, beliefs and assumptions about gender. With reassuring honesty, depth and openness, she draws on her own experience, as well as interviews with gender expansive children and their families, to map out the path to becoming an ally.