My daughter has a island counter top which is a granite tile surface, the corners are to a point and are about two inches away from my grand daughter running into it. What can I do, accept installing a rubber corner, cutting off sharp edge, replacing the whole top?

I think you have answered you own question. If you get a wet grinding wheel on a surface grinder, you can possibly round the edge but a rubber bumper is probably, although not pretty, the easiest solution.