In this paper, I use posthumanism and autotheory to materialize the gendered, racialized and sexualized hair/her/stories of British-Muslim schoolgirls in my study. As an act of feminist indiscipline and a feminist transdisciplinary innovative practice, I entangle with those affective, material, embodied and embedded encounters and stories that grow, escape, flow and glow with the vital materiality of hair and her stories. Hair, as one of the transgressive data of my PhD research, emerged in various temporal, spatial and material contexts throughout our research encounters. Considering hair as having posthuman agency, I argue how it can enable different material relations in everyday lived experiences of Muslim schoolgirls with hijab, body, educational environments and practices. Inspired by the notion that theory can do more the closer it gets to the skin what I call "Posthumanist autotheory," has emerged from the body-theory encounters. I use posthumanist autotheory to materialize how hair as the 'auto' and the more-than-human agency in autotheory grows and becomes matter, method and theory. In using posthumanist autotheory as a feminist transdisciplinary innovative and speculative affirmative approach, this paper hopes to enable knowledge shifts in participatory researching on gendered and racializing assemblages to those everyday ordinary economic, institutional, biological and medical matters and assemblages that constitute racism.