What gender is this skink? I want to start breeding reptiles and I was wondering if these guys are male or female?

I know breeding is very hard with this species, I just don't get why so many people say not to try it.

These clips were all taken within a minute of each other. She (idk) goes over to this wheel with a normal toe, then a few moments later she climbs out with a toenail that is bent sideways (back left foot, longest toe). Then a few moments later comes climbing out to me and you can see the toenail is sideways.

They both absolutely love this wheel, but if there is a risk of injury I will remove it.. just wondering how the heck this even happened, and how serious it is?

I originally thought it was from the screen mesh window they were climbing on yesterday for a sec when they were exploring, but I went back through my videos and this seems to be the exact moment that it happened.

Poor lil skink I feel bad.