Then perhaps go and spend a few days by one of the lakes, or the coast?
I wanted to go see a lake like Lake Como on my europe trip this summer, but I imagine staying overnight may be costly?
I went to lake Como as well - I did a 6 week trip of Italy (with Sicily)
It's perfectly possible to take a day trip to Como from Verona or Milan (which I did), but there are plenty of campsites etc that will allow for budget visits. I think a night or two at Como is a good idea, it's very pretty
Sounds good.....but will i get chance to relax?
She's like a robot marine when it comes to yomping around all the sights.
I think so yes. In Rome, you want perhaps one full day for ancient Rome and one full day for the Vatican. That gives you 2/3 days for mooching about.
Venice is completely surreal and a marvelous place to just wander about. I'm warning you now, you will get lost, it's impossible not to get lost even if you are holding a map infront of you! There isn't a huge amount to do there and wandering around and taking things is the best way to do it. If you want to go to a beach, there is the lido just a short 20/30 minute boat ride away, which isn't an 'amazing' beach but it does the job.
Florence is a beautiful city as well and I absolutely insist you go inside the Duemo and see Michaelangelo's david, they are absolutely staggering.
With regard to museum overkill in Florence / Rome, you just have to keep in mind that you are there to relax. There's nothing wrong with leaving stuff to do for next time and unless you are a total art buff then honesty most of it is passable.
Edit - as above the Cities I have mentioned are very touristy so be prepared for this. I don't think that it ruins its charms though, especially in Venice.