Through their maturity levels and their genitalia structure. Gender is determined by chromosomes A male has an X and a Y chromosome. a female has 2 X chromosomes
Well, you can only have twins RARELY in the sims 2. If you have Open For Bussines, then eat a peice of cheese cake after you woo hoo with your partner. If that does not work, then hit SHIFT-CTRL-C to...