Some will lay as many as 20 so she may not be ready to brood yet. Keep and eye out they can be sneaky and don't want to draw attention to herself or her nest.
If they are toasty warm then she must be sitting on them or something is? If she hasn't been in the barn in 2 days the eggs should be cold to the touch or at least not warm and toasty lol
If you decide to incubate then they will be your responsibility she will not accept them and they won't be...
Something may have scared her off. Nothing you can do except let nature take it course. It's very unusual for a Muscovy to just up and abandon her eggs so I suspect something spooked her.
:welcome