Do they have profiles on WikiTree? Sometimes you can find out where they are from from their naturalization papers or from passenger lists. It would be a lot of work, but if you know their date of birth, you could use Antenati to search through the records. You'd have to go through them by each location in Sicily which is quite a lot, but not impossible.
I notice you are a guest. You should upgrade (free) and create profiles so we can help you get started.