I am trying to find information about whether our train from Sicily to Rome would stop at a station anywhere near Pompeii where my party could disembark for a few hours to sight-see. Then could we get back on one of the next trains on the schedule to continue on to Rome?
Trains traveling from Sicily to Rome stop in Salerno and Naples. Your best option would be to disembark in Salerno and switch to a regional train to Pompei (the city). You could then take a short taxi or bus ride to the Pompeii site (takes about 1/2 hour to walk). There's a free baggage check at the main entrance. After your visit, take the Circumvesuviana to Naples and catch the next train to Rome. Because the Sicily to Rome trains are all either ES or IC and require a reservation, you would buy separate Sicily to Salerno and Naples to Rome tickets. Your Salerno to Pompei and Circumvesuviana tickets can be purchased as you go. For maximum flexibilty, buy your Rome tickets when you get to the Naples train station. There are 2 or 3 trains an hour, so it's not a problem to wait.