She looks like shes ready to give you some eggs,
Very nice little friends, you have there.
Here in the USA , so many have them, they are beloved for their beautiful colors, and temperment !
I'm going to give you 2 different sites to go to and read, alot of info, and pictures on the first. It is Will Wells site a forum buddy here. 
http://www.mountainboomer.com/crotaphytus/
http://www.collaredlizard.com/caresheet.htm
The second is Tom Jones site, and I also like his info.
They both make ofr some good reading, in your spare time.
After, if you have questions, on anything feel free to shoot them to us.
But since you asked a broad question, of "tell me everything about collareds," this is probably the best way to START.
Thanks for posting your pic, they look great, so you must be doing things RIGHT 
Eve