Feminist theorists have long looked to motherhood and mothering behaviour as an important site at which to examine women’s lives, gender inequality and the social construction of gendered institutions. One important line of theorisation has concerned itself with the de-essentialisation of motherhood, a project that I argue remains incomplete, as feminist theorisation of motherhood naturalises biological sex and therefore essentialises mothering as behaviour performed by ‘female bodies’ and fathering behaviour as performed by ‘male bodies’. Using two cases from a larger qualitative interview project with LGBTQ parents, I show that current theories of motherhood fail to have explanatory power in cases – such as gay and transgender parents – when gendered embodiment and mothering (and/or fathering) fail to align as expected. I suggest that research related to queer parenting – particularly research on gay male co-parenting, on the experiences of transgender parents and their children, on non-white LGBTQ parents and on mothering from outside the nuclear family – will be especially fruitful in moving the de-essentialisation of mothering in new directions that will further contest heteronormative, cisnormative and nuclear assumptions about the family.