Dennis - we have done our Europe trips in July and August for the past 10 years because of kids school/camp committments. Okay, so not the ideal time, but not horrible by any stretch.
My top suggestion is to book your accomodations ahead of time. Not sure if you are actually traveling with your daughter or just the two of you - yes, two may have it much easier than 3, but still, not worth the time you will need to spend on the days you are looking for a hotel. So - plan carefully, start booking now (but only places you can cancel for no $), and then tweak when late spring comes along.
Our last trip that was in August actually was Austria/Germany/Prague. One important thing is that even in the northern countries you can still have very hot weather. We (husband & I anyway) don't sleep well in hot weather. A second tip would be to spend the additional money to have A/C in ALL hotel rooms that are in cities. We were able to do just fine in the small B&B outside of Salzburg - it was still pretty warm, but there was a fan and we had the window open. This would NOT have worked for us in Prague & Vienna - too much street noise and the air was just too still, so look at the various places you are staying and consider seriously the A/C upgrade. You'll need it in Italy for sure.
Otherwise, you will be on vacation with the rest of Europe, so what a great time to go! We met our English friends in Cornwall during one of our late summer trips - their kids don't even get out of school till late June - and we've been back a few times to meet them in other cities, also in July/August. It will be wonderful!