This could be a tough one, but consider this via car, Freibirg to Munich (day 1), Munich to Sazlburg and then to Venice via the Brenner pass (days 2 and 3), Venice (day 4). Venice to Florence (day 5). Florence (days 6 and 7). fly out of Florence????? May be too ambitious.....comments from others????

If this may be your mother's only trip to Europe, where is she most interested in visiting (other than London and Paris)? Is Florence her definite choice?

As you probably know, Florence and Venice will be pretty crowded in late July. So, you don't want to compound the crowds, heat, and lines with too much packing and unpacking and struggling on and off public transportation.

Sometimes when planning a trip, I find one fixed point (point of arrival or departure or the #1 must visit), then make a huge list of everything within reasonable traveling distance that I want to see. Then, I start paring down and prioritizing. The next step is to lay out a map and a calendar and start penciling in your (and your mom's/your boyfriend's) top sights and the amount of travel time between locations. Just an idea ... it gives me a better grasp on the logistics.

I took my mom to Venice and she says she wouldn't have missed it for the world. Not sure what your mother's tastes are, but I can't imagine not taking her if it's her only trip to Europe.

How about Venice for 2 nights, Florence for 3, and the last 2 on Lake Como (maybe Bellagio) for the gorgeous views and to unwind from the quick pace - plus, you and your boyfriend can reach Malpensa for a morning flight without having to spend one of your few nights in Milan. Then, if your mother and sister wish, they can take the RyanAir Milan-Bergamo to Paris-Beauvais flight very cheaply to continue with their vacation.

I hope that you have a wonderful time planning your trip ... the short amount of time of work is limiting but it still sounds like a lot of fun!