Ultimately we would need them to be mothers. They will have the choice of being artificially inseminated or they can be bred by the strongest most handsome male models (to ensure the beauty of the child) who will be brought over in slave ships. Of course once they impregnate the woman with a girl they will be sent back. Being a mother will be the most respected role and they will have the most authority. If a woman does not want to be a mother than she is free to leave the island.