Help needed planning mother daughter trip to Italy

Could you clarify what you mean by “southern Italy”?

Looks like you have 8 nights in Italy so stick with 2 or 3 locations.
You can’t go wrong just spending all your time in Rome with a day trip or 2

If you don’t have flights already you might consider a combination of Rome and Florence like this with train between

https://www.kayak.com/flights/BNA-ROM/2023-03-10/PSA-BNA/2023-03-19/f769d74c2e2c3e71ef0ce4f87fd5cb6af/2adults

Or I agree with above Rome for the entire time with a couple of day trips.

It's a very short time, so I would also suggest spending time in Rome and then perhaps a side trip to Pompeii, Sorrento and perhaps a tour to the Amalfi coast. Rome is absolutely wonderful, but do some research before you go. There are places, like the Borghese Villa museum where you have to have advance tickets...and well worth it. I would advise you getting Rick's book on Rome and then taking his advice to take pages from it when you are out for the day. Don't worry about taking the trains. We have found them to be affordable, on schedule, clean and safe. You're going to love Italy.

Thank you for all the suggestions. My daughter is very interested in flying into Naples. She looked at towns of Amalfi, Positano, Sorrento, Capri, and Palermo and likes but which would work if we stayed in Naples.

Palermo's in Sicily, which needs about 2 weeks all by itself. Even spending all your time in Sicily would leave you seriously short, so I urge you to hold off on Palermo until a later trip when you can include some of the other wonderful spots down there.

I'm not sure all the Amalfi-area spots are great in March; others will be able to comment on that.

March is too early for the Amalfi region
Ferries won’t be running yet
Amalfi, Positano will be mostly closed up

Sorrento would be ok

I wouldn’t recommend Naples as a first time in Italy

I would not recommend sleeping in Naples. It was very dirty and hectic. Not relaxing at all. Sorrento is amazing though very beautiful. I day tripped to Capri, Amalfi Coast, Pompeii.

While I'm sure well intentioned as just an example, the flight described by that Kayak link would be a disaster, with the trip over taking close to 40 hours. I'm surprised Kayak would even offer it. Is the OP really on such a short deadline that the flight needs to be booked right away? Please take some time to do some research before committing. This sounds like an important trip for both of you, so please don't rush into something that you may regret later.

I took my college aged boys to Italy a few years ago. We did the Rome-Florence route. Amalfi with not be enjoyable in March. Posters are correct in that a lot will be closed up. That is a trip best saved for warmer weather. Spend a few days in Rome, then do a day trip or a night in Orvieto on your way to Florence. It's a lovely hill town. There is a lot to see in Florence as well. Or, spend all your nights in Rome and day trip to places. There is lots to see in do in Rome itself and surrounding areas.

Based on time of year I have to agree too early from Naples. You wouldn't get the full experience since most of the ferries won't be running and stuff is closed for off season. You could do Florence and Venice just bring layers for chilly weather.

Ditch Naples, it's the only town in all my travels around Italy that felt really sketch. With just 7 Days I agree with all the other posters, 4 days in Rome and 3 days in Florence. You can fly in and out of Rome, by taking off for Florence on the day you arrive then spending your last days in Rome.

The "quaint" towns you mentioned are often not accessible by train, maybe a bus, but with no car it is better to use the really efficient train system that they have in Italy.

Part of Risk Steves travel philosophy is that you will go back, and when you do and you want to do the Italian Riviera I would base in Sorrento.

You have to consider where you are from and where you have been in evaluating what you will think of Naples. Clearly some respond negatively to it, but it is an exciting city with thousands of years of history. It is not quaint but it is delicious. I could easily fill a week+ there, and it is where I would go at this time of year, but you could also easily do half Naples and half Rome.
IF the weather is good, you can combine Naples and the coast, but don't expect everything to be open.