Fertilization requires physical contact between a hen and rooster. If they've been together in the ~two weeks prior to those eggs being laid, even if it was only a few hours out ranging around, then yes, the eggs might be fertile and could hatch. Otherwise, no, she's sitting on duds.
Some people will let a hen sit for a while and then try removing the eggs and replacing them with purchased chicks. They usually do this in early evening so she sits on them all night and that's supposed to make her more likely to accept them in the morning. If you want her to try her hand at the mama hen job, that's another way to go about it.
