If the world would only have 3 people and they were all girls how would they reproduce?
One would have to be some sort of doctor to do the artificial insemination, then they would need to find a sperm bank that's the only way I guess.
one could give another one a gender change and they would take turns?
What's the question you see Jesus was born ????
They would take that shot or whatever
Unless they evolve into asexual beings in a short amount of time, they cannot reproduce without some form of artificial insemination.
Experiment with other animals?
They'd have to go hit up the sperm donation farm.