This paper uses intersectional feminist theory to examine girls' unique positioning at the margins of age and gender. Using a wide range of examples, I consider that girls are marginalised within the category of children as female and within the category of women as children. These intersectional marginalisations reinforce one another and result in a further denial of girls' rights. A study of international human rights law demonstrates that fragmenting girls' identity into the categories of "women" and "children" causes girls to be overlooked in favour of those who are more visible. I suggest that the discourses of women's rights and children's rights must work together to establish an integrated approach to girls' rights. I propose that the appointment of a United Nations Special Rapporteur for the Girl-Child can bring this to effect in international human rights law.