Extending travel time in Europe?

With 5 extra nights, I'd be more tempted to extend the time in Rome by 2 nights. There is so much to do there. The day and a half on the tour will cover the major highlights, but not give you time to really explore. Then you can choose either CT or the Lakes for 3 nights (my preference would be CT) and not have to move around so much. The tours are paced well in general, so I think you would be able to enjoy a few post-trip days.
I would also consider adding a day or two to the front end in Paris-get over jet lag before joining the tour. And again, there is so much more to do in Paris than you will have time for with just the scheduled tour time.

I wouldn't be too tired for some much-needed R&R at the beach for a few days at the end of a vacation full of go-go-go sightseeing. In fact, the CT after Rome would be perfect. Doing both the lakes and the Cinque Terre is somewhat redundant, however, IMHO, especially back-to-back. I visited the Como area for a couple of days near the beginning of a trip and the CT near the end. I ended up thinking I could have better spent those lake days in Milan or Verona and thought the CT was the better of the two. They're both great yet different experiences...I just didn't think so many R&R days were needed for my trip. That's just me. Plus, they're far apart. If it were me, I would pick just one area...and it would be the CT in this case. If you were ending in Milan, I would suggest the lakes. Then again, if you're flying out of Milan, the lakes are certainly convenient and a good place to stay for a last night before heading home. Whatever you decide, I'll recommend these hotels highly: Albergo Milano in Varenna and La Torretta in Manarola.

Shayla, You don't say how old or in shape you all are. I have done most of my traveling independently, but the 1 RS tour I took I arrived 3 days early and did some touring on my own, followed by 14 day tour, and did an additional 3 days on my own after. I was 48 at the time and in reasonable shape. I could have easily kept on going (if only I had the time and money:) I think most people are not worn out at the end of a tour, and could easily continue on.

I don't think you will be too tired, but I have to agree with Michael that both places don't have much to do there besides relaxing. Unless you plan to hike in CT of course. I spent 3 nights in CT, then traveled to Lake Como (Varenna) for 3 nights. It was a bit too laid back for me, though admittedly I am not very good at relaxing for long. If we hadn't kept busy all one day at Lake Como with a cooking class (lots of fun!) I might have been bored.

Shayla, I normally travel for awhile after finishing a RS tour (sometimes for another month), and the two areas you've chosen would be fantastic places to "wind down" after the tour. When you're on your own, you'll be able to structure your activities according to what you feel like at the time, and that can be very restful and enjoyable. Visiting the C.T. and the lakes (especially Varenna) would be an excellent way to end your trip! Happy travels!

It will be fine. If anything, you will probably feel more confident finding rooms, cash and food at the end of your trip.

it sounds like a good plan, both places are good for winding down you could do 2 nights CT and 3 nights at the lake either way you will have a nice time I have started trips to Italy at Bellagio in Lake Como just to recover from jet lag before taking off though Italy
both areas are beautiful and a slower pace than the big cities

it is doable. I would not extend my stay in Rome after a fast RS tour, but head immediately to the CT area. Just one small note: there is no such thing as a "lake district" in Italy. I'm not criticizing you, just saying that if you try to search on the Internet, or speak with people there of the "Lake district", it will sound very strange.

'there is no such thing as a "lake district" in Italy' Googling 'lake district italy' : About 4,290,000 results (0.14 seconds) I'd go ahead and give it a try.

Shayla, I think it's a great idea to spend a few extra days in Italy. It will give you a nice chance to wind down before you have to return home and back to "real life". I've done several RS tours and the best advice (other than packing light) that I got was to arrive a day early to get over the jet lag. The folks that don't will probably be falling asleep at dinner the first night! So, my advice would be to use 1 of the extra days up front in Paris (I love Paris). If you do decide to go early and stay at the same hotel, let them know that you're on the tour and they'll give you their best rate. Check your guidebook, there might be a special offer - I once got a free ticket to the Bateau Mouches (Seine boat ride) for staying an extra night. RS tours are great and you will have a wonderful time with your mother and sister!

Shayla, A few more comments..... I'd suggest heading from Rome directly to the Cinque Terre. There's a direct train from Roma Termini to La Spezia Centrale with a travel time of about 3H:45M. Towards the end of the trip, the train travels along the coast, and seeing the azure blue waters of Liguria will be a fantastic pre-cursor of what you'll be enjoying for the next few days. In planning that part of your journey, be sure to allow for the travel time from the C.T. to Varenna. I haven't looked, but it will likely be at least a five hour trip (via Milano Centrale). I assume you'll be departing from MXP? Cheers!