I like the idea of rogue females that can steal babies, but not so much the idea of them breeding with your males to make more rogues. Rogue males at least have the benefit of bringing newer genes into your tribe, but females would literally only increase the number of hazards down the line and use valuable turns that could be used for gathering food or fending off predators.
But on the note of them stealing babies and becoming hostile, it would likely then need to be the case that they have at least one gene to make them a possible threat.