Hello and welcome.
I see you mentioned possibly taking one of the beardies back.
Well, just wanted to say that they are addictive, and even if you start out with one, and say no more, you would probably get another one in time. :lol:
So I say might as well keep it now, save yourself the trouble in the future! :lol:
Seriously though, if you do keep them, I would separate them. Even if you could put one of them in a 20gallon until it gets a little bigger, and you could get another setup in time.
(and just as an example of why to separate them, look at the pic of Foster in my sig. Look at his right front leg. He lost his front leg to one of his siblings when he was only 4 weeks old.)