How realistic is having a broody hatch fertile eggs?

[Dawnclucks22]

First off, I don't have a rooster. I have a flock of 5, made of 4 standards and a bantam. I'm also not completely sure that this hen is broody yet, but it's possible in the future that we may try hatching under a broody.
Also, the one broody is a bantam. A half-serama bantam mix. Is it possible to have her hatch standard eggs, or only bantam eggs?
Third, is it possible to do this without a backup incubator?
One more thing - will I have to separate her, and if so for how long?

 

[Trux]

When my better half was growing up, they had a Banty and she would sit on eggs, and she would steal eggs from other nests. She would tuck them under her wing and bring them back to the nest. From all that my gal has told me about that one little chicken, she was one fierce momma, so I would say you have a good chance of her sitting to term. She raised a lot of clutches for them over the course of a few years. As far as having an incubator, I believe it would be a good move and could save your hatch if your broody decides to leave the nest.

 

[Trux]

Oh and IMO I would put her in her own area away from the other so she won't get disturbed, and she can have peace and quiet