Framed by relational dialectics theory (Baxter), this investigation considered the meaning(s) of motherhood in female-female co-motherhood. Analysis identified two competing discourses: (1) discourse of essential motherhood (DEM) and (2) discourse of queer motherhood (DQM). Speakers' invocation of the DEM reinscribes the mainstream US cultural discourse that children can have only one authentic (i.e., biological) mother, whereas invocation of the DQM denaturalizes the DEM's presumptions of authentic motherhood as biological, interrupts monomaternalism, destabilizes the patriarch, and troubles the equation of biological with moral motherhood. Whereas interpenetrations of the DEM and DQM were typically sites of adversarial discursive struggle, in a few instances, the DEM and DQM rose above their antagonistic relationship, combining to create new meanings of motherhood.