Thanks for the advice! I felt her butt and i didn't feel anything that resembled an egg. They're three years old and the shell on the larger of the two is about 9" long. When do i have to worry about them reaching sexual maturity?

And it is safest to keep them separated right? It would be lots easier to put them together but with the reputation snappers have for agressive behavior i thought it would be best to keep them separate.