Depends on how long she left the eggs and whether they were viable in the first place. They can survive a pretty long time away from the hen.
I have one hen who set thirteen, hatched eleven, one died in the shell, walked away from the last egg. I knew that egg was a day behind, so I kept it in my bra all day, and then when she went to bed, I stuck it back under her. I ran out the next morning, only to find that she'd moved during the night, and that the egg was cold as a rock. It was still peeping, so back in my bra it went.
Hatched a perfectly healthy chick who turned out (of course) to be a rooster.