Hi Shelley,
It sounds like you may have 2 little males, but I'd have to see a picture of their vent area to be sure. A lot of times the females will have a dark spot on both sides of the base of the tail close to the vent. Males won't have those 2 spots, but on some females they can be difficult to see, especially when they are very young, and depending on the species/subspecies the spots may not even be present. The post anal scales and the hemipenile bulg at the base of the tail/vent area is a definite way to tell if its a male because the females won't have them, but it can still be difficult to sex Collareds when they are very small especially in some species. Post a picture of your little ones and of their vent areas and I'm sure someone on here can give you a good idea of what you have.
Jeff