I'm with the Melissa on this one, there's no fluff currently supporting the idea that the Space Marines are policed by the Adeptus Sororitas. In fact, the Space Marine chapters are akin to Imperium-Dedicated Mercenaries, answering the call of imperial powers at their own discretion. Literally the only power that can directly and by its own authrority call upon Space Marine chapters for support are the Inquisitorial Ordos, and generally only those of the puritan (rather than radical) philosophy.