What about making the game so that if female settlers are brought, the free colonists are able to produce more free colonists? This would necessarily mean that extra food would be used, but production bonuses could apply, since the morale of the men would be greater.
Another thought: the female settlers could also marry skilled laborers. This would, of course, still produce free colonists.
each colonist is already a abstract grouping of men and women.
Right, but it could be an added element. I mean, we are allowed to make some changes in gameplay in between FreeCol 1 and 2.