We also go Tuolumne every summer. Our son is the same age as your daughter. Like you, we haven't been to the Valley for around 10 years. Even then, it was much as you described it with the congestion, etc.
This past summer, I did a day hike up to Donohue (
http://www.highsierratopix.com/community/viewtopic.php?f=1&t=12987), and ended up talking to a NOBO PCTer on the way back to the campground. He mentioned that he & his friends were planning on going into the Valley the next day. While having never visited before, he had heard it was quite "different" from the quiet solitude of the PCT. I laughed and said "you ever been to NYC?" He said, yeah, but then I said "how about Times square on New Year's eve?" Well, maybe it's not that bad, but closer than not. I concluded by saying if you've never been, well obviously you have to go, but be prepared to be disappointed with the crowds.
As far as population growth, California for obvious reasons is in a league of its own. We're fortunate to be able to travel, and it's definitely somewhat ironic that places like Italy (Rome & Florence), which had/have a reputation for being crowded, thus providing the primary driver for emigration to the US, are now in comparison quite quaint. Outside the main city centers, it's essentially countryside the way I remember Calif in the 60s as a kid.
Anyone my generation knows what I'm talking about: virgin rolling hills that would be (and have been long ago) attacked by bulldozers in Calif, and yet peacefully just going on the same way they have for 1,000s of years. While pop growth is a world wide problem, there are certain places that are somehow seemingly escaping the crush. I'm talking E Europe, Croatia, etc.
