It is not unusual for chicks to hatch a day or even two early or late, whether in an incubator or under a broody hen. That chick hatching two days early doesn't mean you have a staggered hatch. A staggered hatch is when the eggs start incubation days apart so hatching is days apart.
Before they hatch the chick absorbs the yolk. They can live on that yolk for over three days before they need to eat and drink. That's nature's way to handle the chicks not all hatching exactly in 21 days. I don't see that you have a problem with that just because of the early hatch. The problem with a staggered hatch is not early hatching, it's that some are very late.
The problem with a real staggered hatch is that the first to hatch get hungry and thirsty after a while and Mama has to decide whether to take the hatched chicks off to find food and drink or stay to hatch the remaining eggs and let the first chicks starve. They practically always abandon the nest to take care of the hatched chicks.
There are different ways to handle a staggered hatch. You might let nature take its course, the late eggs don't hatch. You can put the late eggs in an incubator and try to hatch them yourself. Some people try to make a homemade incubator just for hatching. Or maybe another hen is broody. Some people try to remove the chicks as they dry off in the hope that Mama stays on the nest. Sometimes this works, sometimes it doesn't.
An unplanned staggered hatch is usually very stressful and often not successful, at least with the later eggs. That chick hatching early does not mean you have one. You are probably OK.
The next time you have a broody and want to hatch eggs, collect all you want her to hatch and start them at the same time. Mark them and remove any unmarked eggs daily if any show up. That way you know you don't have a staggered hatch.
