Not even sure this would work but,
The thaan's sperm has a single X chromosomes.
The shen's egg has a double XX chromosomes.
The zhen has, of course, no chromosomes.
The chan's sperm (like the thaan), has a single chromosomes, however the chan possesses one of four different chromosomes, it is the chan alone that determine the gender of the future child. I have no idea how the four chromosomes would be shaped.