Look in between his or her legs, if you see visable dots that shape some sort of wide V you got a male,
If you dont see holes and just see a V aligned with the skin, you have a female.
That white thing can be a few things...
1.) Fat
2.) Ovalating a Egg with no Embryo
3.) Egg with Embryo.
If its a male, im pretty sure thats just fat. If its female, and hasnt been exposed to a male, then she may be having her period. Its rare but lizards have it too. Or if there has been males and female encounter, you may have a egg.
But just to add, all I see is 1 little white thing, eggs usually come in pairs. On lower right, one upper left, some side by side, but you usually can notice both of them at some point.
If you want, putting a bright light to the left or right of her stomach can reveal the egg surface thru her skin..(if that makes sense to you, its like sonar just by shadow and skin, =]), My leos Pregnant right now, if she didnt block herself inside the humid hide to lay her eggs, Id show you what her bottom looks like.
good luck
-----
Normal - Male - Ninja
High Yellow - Female - Ninjete
Normal - Female - Lizzy
Norm/High Yellow - Male - Ninja II