Originally Posted by sandrac8388
Yes she does. What is that? Is her stomach exploding? =o
That's her ovipositer, or "egg spot"- where her eggs come out of. That means she's almost definitely female (not 100% though because I've heard that some young males can have a fake one).
Also I just re-read your original question and I misunderstood it the first time and I thought you were asking how to know if she was definitely female.