Usually if they are with eggs they get quite tubby, has she been near a male! When my female was preg she was anything but still....she just dug about everywhere like a nutter!
My male beardie is very lazy sometimes doenst move for days as he conserves energy but he has been constipated afew times and when he is like this he gets very grumpy looking and stays in the same spot...he doesnt seem to brighten up either!
Would look at as mentioned temps, if you think she might be constipated then apple sauce and plenty of baths work or it may be that she is brumating? Is she normally very lively! x