Is my crested gecko actually a boy?

I always thought my created gecko, Waldo was a girl when she reached adulthood (she's now 3 years old) because she only ever had a small bulge down there but, yesterday when I was putting her back i noticed there's a little space between her bulge so im wondering if she's maybe a boy with small cresticles?

Also the other photos after the first one I posted of her are old, she's since been on a diet and is at healthy weight again!