As historically construed, both engineering culture and school science culture marginalize girls. With the focus on engineering in the Next Generation Science Standards (NGSS), engineering education researchers have called for a more targeted investigation of how girls at the K-12 level engage in engineering. This study investigates, through critical participatory ethnography, how 6th grade girls engaged in an Engineering for Sustainable Communities unit (EfSC) guided by conceptual frameworks centered on Cultural Ways of Learning and Rightful Presence. Three in-depth cases are presented that explore the kinds of engineering problem spaces girls chose to address through iterative design of functional prototypes. Findings reveal, first, how anchoring engineering in girls' embodied experiences supported new forms of participation, new roles for embodied experiences and new making present practices, thereby solidifying a more equitable culture. Second, as the girls moved and hybridized embodied community/STEM ideas and resources, they organized and put into action (through decisions made while "doing" engineering) their values, ideals and desires and that of their communities. Third, we found signifiers, themes, symbols and practices of an emergent engineering culture in which girls positioned themselves as able. These effected engineering for social-spatial justice using a technically rich and socially specific iterative engineering process which seeded a rightful presence for girls in middle school science.