so whats the concern about the Naples train station?

No idea, I didn't find it that way and I traveled alone as a 20-some year old. I think some folks may be talking about the station before it was modernized, but look at Google photos for yourself. There's nothing wrong with it. Maybe people are commenting more on the people who hang around the station than the station itself - again, I have no clue what these comments are about, and I would take isolated comments like that with a grain of salt. Why are you worried about it? Anyone who has travel experience under their belt should be able to handle a modern train station in southern Italy or even the Circumvesuviana, which folks complain about endlessly.

Some people aren't used to urban environments. If you live in the suburbs at home and aren't used to cities, the the area around Naples train station may feel a bit unnerving - but so would my own neighborhood in the US, honestly. Otherwise, nothing to fear, especially if she isn't going outside the station. I walked from the station a few miles around Naples about ten years ago (the station had the same "sketchy" reputation back then) and wouldn't raise an eyebrow about the "sketchiness" myself. But I am used to cities.

Just tell her to be very careful about pickpockets on the trains and in the stations - that includes all train stations in Italy.

I too have read the warnings about Naples' station and others. I was a little worried about our 1st European train to catch out of Rome Termini last year. Turns out, it was fine. Safe and very easy to navigate. I am used to Penn Station in NYC. Since you are from VA, maybe you are used to Union Station DC.. I suspect that if you are comfortable in US stations like those, you'll be fine. Just be aware of surroundings like you would in the US.

Now watch.. I will be in Naples Centrale in May, and after sounding like a big shot, I'll get mugged or pickpocketed!!!

It was some 25 years ago, but friends in Florence who were quite used to the hustle & bustle of that city warned me that in Naples (not in the station, but out on the street) I should not carry a purse with the shoulder strap outside my jacket. They said thieves were known to whizz past on motorbikes, armed with knives, and cut the strap of a purse while grabbing it. Putting the purse under my jacket seemed like an easy precaution so I did it. No problems occurred.

Another time, though, in Rome a "helpful" man stopped me and pointed out that I had a smear of ice cream on my jacket. He offered me a tissue to wipe it off. A friend who lived in Rome said this was a common technique to rob tourists. I declined the tissue and walked away from the would-be thief; no possessions taken, but I had to get my jacket cleaned.

The Napoli Centrale is big, open and modern. It's also very crowded. The issue, from my experience over several years, is with the Circumvesuviana line that goes to Sorrento. This train is old, not very clean, very crowded and has a history of pickpockets (personal experience). Keep your things in a safe place and stay alert and there should be no problem. Other options are taking a car service (about 70 euro) or a boat (my favorite - it feels like the vacation starts before arriving at the hotel).

like you we have used it to get to sorrento twice now and if you 'hang' around and act like a tourist then you might experience something. but walk with purpose and be 'sensible'. (like not wearing your money belt on the outside of your clothing and not standing in the middle of the station looking up at the signs) don't let people offer to 'help' you.
we have caught the bus to sorrento twice from naples airport ( it leaves just outside the airport door) and is inexpensive and drops you at sorrento train station. no problem. this is one option but relies on getting to the airport. ( there is a bus- but perhaps not a good option)
if you are catching the local train to sorrento, then read up on your options. ( do a search in the tab at the top of the screen)
hope this helps

I may be a over worrying husband

Jim, I use this station at least 5-10 times each September. My daughter lives in the area and we use it often. It's busy, but by no means any different than some of the larger stations stateside. There is also visible police presence. As with all travel, she just has to be aware of her surroundings.

I would recommend looking at the helpful resources on this website. The travel tips section will address your questions and concerns. Great information for the solo traveler.

I used it a couple of years ago when traveling from Rome to Sorrento and back. I never had to leave the train station, and felt perfectly comfortable in it. I can get to feeling uncomfortable in some urban areas, but being inside the Naples train station didn’t bother me at all. I wouldn’t worry about it.

If the Circumvesuviana line in Naples is still in the downstairs area as it was when I was there several years ago, then yes, beware. Our train connection was late, so we were at the tracks waiting for about half an hour. Many scammers approaching the waiting passengers. We never saw any police or authority people. The train (to Pompeii) was crowded with standing room only and pickpockets were working the aisles with kids doing the distractions, and 'musicians' playing and asking for money. These were easy to spot, but who knows how many other things were happening. Just be careful, aware and follow the security suggestions found on this forum.