Generally accepted that pigeons normally become breeding active after about 6 months. Another thing pigeon keepers are concerned about,, is the maturity level of young pigeons. The younger ones tend to be less good than mature pigeons as parents.
If your pigeon sits on egg/eggs and they hatch,, then your hopes are, they get fed, and weaned. There is a possibility that the egg layed is not a fertile one. (more common with young pigeons) Not much to loose at this point.
Another thing about pigeons,,,,,, they usually lay a second egg within a couple days. 2 eggs is the norm. There are exceptions of course.
The bad part of this hatching,, is the time of year.
I do not know your general location, but if it is cold winter climate,, success really dwindles.