1 week: Rome, Florence, Lucca, with kids!

What is your arrival/departure points in Italy?
Where are you coming from? ( i.e., jet lag issue)

I always worry we are packing too much in

That is a legitimate concern

A rental car is not your friend for the places you list.

The train service is good up to Florence. And also over to Lucca from Florence.

The kids can ride the walls at Lucca on rented bicycles.

I agree that more info would be helpful. It appears you plan to arrive in Rome, but will you be flying home from Florence or Rome? It makes a difference in optimizing your itinerary. If you are arriving on a flight from North America, and especially with children, I would be concerned with how jet lag will impact everyone on their first day. Given that, the very short amount of time you have, and the shorter daylight hours, I would be tempted to eliminate the stay in Lucca. Divide your time between the remaining 2 cities and visit Lucca as a day trip from Florence.

A car would be more hindrance than help in these places and they are all accessible by frequent trains.

Only a week, consider spending all of it in Rome, forget the rental car.

I think it’s great that you are traveling to Italy, but if I read your itinerary correctly you are giving yourselves only one full day each in Rome and Florence! For me the pace of your trip would be a recipe for frustration. I wouldn’t characterize Lucca as countryside and agree with the advice to skip it.

Hi and welcome to the forum, Sabrina!
As above, I don't think you have time for quality visits for 3 locations in 6 nights: 2 nights only give you 1 FULL day, and that's a very short time for Florence and Rome. Yes, depending on where you're coming from, jet lag may be a factor on arrival day, and it's important to know which airport you'll be departing from as you're going to want to stay near it the evening before your flight.

I'll vote with the recommendation for 3 nights Rome and 3 nights Florence. If flying both in and out of Rome, you'll want to take a train immediately to Florence on arrival day, and end your trip in Rome. No, don't even think about renting a car for this itinerary as it would be more hindrance than help. Yes, a car is useful for exploring the Tuscan countryside but I don't know how you'd fit that in unless you choose not to explore Florence itself. As well, daylight will be short in November.
Assuming you're flying both in and out of Rome, this is how I see it:

Day 1: arrive Rome and take a train to Florence. Sleep Florence (partial day)
Day 2: explore Florence - sleep Florence OR rent a car for the day and do some countryside
Day 3: day trip to Lucca via rail OR skip it and explore Florence; sleep Florence
Day 4: train to Rome; sleep Rome (partial day)
Day 5: Explore Rome; sleep Rome
Day 6: Explore Rome; sleep Rome.
Day 7: fly home

If you're flying out of Florence the order could be reshuffled. Another thing to be considered is what you're planning for sightseeing in both Florence and Rome? Not all attractions are open every day so you wouldn't want the one FULL day you had to work with be the day some of those things are closed. You're also going to need advance, timed-entry tickets to the any of the biggies.

Editing to add: In hindsight, just staying in one place (Rome or Florence) for the entire time - as others have suggested below - is a pretty good idea. Day trip as weather and whim allow (Florence is a good base for that). As janettravels44 offered up, the original plan risks the family coming away hating Italy; most people I know who've said they disliked both Rome and Florence tried to do them on the run. It can take a little time to acclimate to where you are and how things work.

This is a great way to make sure the family hates Italy. This is all logistics and almost no time at all to see anything or do anything. Someone gets a tummy ache one day -- which is likely with this rush rush schedule and then what do you do? I'd drop Rome or Florence and choose one Tuscan town to visit. e.g. 3 nights in Siena and 4 in Florence. -- or 4 in Rome and 3 in Montpulciano If it were me I'd base in either Rome or Florence and then day trip to another town or two. You could do Lucca or Bologna and Siena from Florence. And Orvieto and Tivoli from Rome.

I suspect your flights will be RT Rome
If that is the case I wouldn’t waste any time on transit- with 6 nights you've only got 5 full days to sightsee
Stay in Rome the whole time and plan 1or 2 easy day trips
Orvieto and Ostia Antica

Or you could travel immediately to Orvieto on arrival - just over and hour- spend 2 nights in Orvieto then remainder in Rome

Days are short in November and the weather can be iffy

I agree with JanetTravels44 above. A week is really short. If you're coming from the states you'll have jet lag added in. I'd pick two locations. If you have to see Rome then maybe choose someplace like Orvieto or maybe even research an agriturismo if that's more your speed.

But with that short of a timeframe, I'd probably fly in and out of Florence and spend half of it in Lucca or go south to Siena or a hill town.

Note: Lucca is a great compact town and it'd be awesome for kids but it's not at all "countryside"

We took our daughter to Rome and Florence the summer after 6th grade. With kids those ages, I would spend the entire time in Rome and take a day trip to Pompeii. I love Florence for the art, but that is probably not important to your kids. If they are cat lovers, you should go to the Largo Argentina ruins and cat sanctuary in Rome. I assume you know that you will need to be in the city from which your flight leaves on the night prior to your flight.

Thank you all--this is so helpful and confirms my fears! We live in NYC so I am hesitant to spend our whole trip in Rome as we need a bit of a city escape. As of now we are flying round trip out of Rome.

How about this for a re-write: 3 nights in Rome. Rent a car and drive to Florence. Perhaps spent one night in a hill town on the way? Drive rental car to Rome airport and depart. Alternatively, 3 nights in Rome, rent car and drive to Montepulciano or San Gim. Stay there 3 nights and drive to Rome airport and depart. Skipping Florence. Thoughts? We could also consider buying a one way from Florence to Rome on the day of our return flight but I'm nervous about late flights and connection times...!

If you depart from Rome you will need to stay IN Rome the night before

Rome 3

Rent car drive to hill town of choice 2-3 nights
( no Florence, no car there!)
Return car somewhere along the way back and take train into Rome
Chiusi is a good option
Orvieto only has Hertz

Rome 1 night

How many nights in Italy do you actually have?

See if you can change flight to depart from Florence?
Those flights usually leave later in day

I have been to San Gimignano and can't imagine spending 3 nights there. I would consider Orvieto as a place to spend a night or two.

We arrive Sunday, depart Sat, so 6 nights. Flight out of Rome is at 1430...

There's a fast train (3 hrs) between Siena and Rome. Perugia is close to Rome on the main train line, Orvieto is even closer.

It sounds like you want Rome and a smaller "Tuscany" experience. Car/bus accessible towns like San Gimignano, Montepulciano, Montalcino and a ton of other little towns are super evocative but like someone mentioned - three days is a lot, especially given that it's HALF of your vacation.

If I was flying into Florence and barnstorming Tuscany, I might think hard about a car, but that's not what you're doing.

TLDR: Rome 3, Orvieto or Siena 3. No car.

The Tour Guy, tourguy.com , does a full day trip Rome to Pompeii and Sorrento for a nominal fee. My adult daughter and I are taking this after a couple of days in Rome. Then fast train from Rome to Florence and they also do tours from that city. Take it easy or you’ll go batty.

Clarifying the above, we aren’t certain about doing a half day in Sorrento after Pompeii. It might be poor utilization of time in bus travel. We haven’t booked the day yet. I’ve been to Sorrento so I’m just conflicted. Transport from Sorrento to Venice where we are heading the following day isn’t optimal. We would go back to Rome and take the high speed to Venice (that my daughter really wants to visit). Suggestions appreciated.

We arrive Sunday, depart Sat, so 6 nights. Flight out of Rome is at 1430...

That being the case, go to the 'other' location first and spend your days in Rome at the end.

Trying to do 3 places will likely result in you saying at 1530 on departure Saturday ....."What happened....?"