State legislatures in the United States have become increasingly antagonistic to the rights of transgender individuals, with hundreds of new bills being introduced each year that seek to limit the ability of trans people to fully participate in public life. This means that state legislative spaces have also become central to trans advocacy – a space where advocates must interface with legislators on definitions and understanding around the concepts of sex and gender. In this project, we conduct a discourse analysis of committee hearings of anti-transgender legislation in two states, Arkansas and Arizona. We find legislators attempt to stave off critiques of discrimination against trans people by framing their legislation around a paternal need to protect girls. The discourse in these legislative spaces not only embraces a strict gender binary but also emphasizes the need to safeguard the “inherent” vulnerability in children assigned female at birth and the experience of girlhood.