I agree with everything said. I know you have good intentions for your beardies and obviously care about them very much, so please let us help you. :wink:
I would dump the sand for sure, and make sure that wood is sealed really well. Since you were able to make your viv so quickly, maybe you would be able to make a new-and-improved version: Melamine doesn't need to be painted or sealed, and you can just use pure silicone to seal the creases on the inside. That is how Dudley's viv is made.
I know that people will eat burgers and other not-so-healthy foods. But feeding your beardie a sub-adult mouse would be the equivalent to you eating a burger filled with whole bones that is bigger than your head, in one bite. :| If you want her to have a snack to munch on, try hornworms. They make awesome treats.
And also, I think that your female looks far too small to breed. They need to be at least 18 months old, and a minimum of 350g before you want to even think about breeding.