So you say they remained female. But if you notice in the books of sorrow the worms refer to all three as princes. What I have inferred so far is that gender is not the same to them as it is to us. Sorta goes like this. You are female if weaker or lesser. You are referred to as female if the if the subject referring wants you to believe you're lesser. (You see this when all three refer to each other as sisters) You are male if you are more powerful You refer to yourself as male if you claim to be more powerful.