I’m from So Cal and I still spend a lot of time there. I attended CSULB. IMO, most schools mentioned so far are going to have the type of people your daughter wants to avoid. That’s So Cal, generally speaking. But as with all things, not everyone is going to be a stereotype. She can find her people anywhere.
If she wants a more relaxed vibe, the CSU’s might be a better bet. They are probably more diverse and less expensive than UCs. CSUFullerton and CSULB might be worth a look. I think there are more residential students at CSULB in particular.
Which Cal Poly? SLO or Pomona? Cal Poly Pomona might be a bit more down to earth than SLO in terms of what your daughter wants to avoid. Cal Poly SLO is going to have a different climate to that of the So Cal colleges as it’s a fair bit further north. Still nice though.
For privates, she could consider Biola, Loyola, and Whittier. I don’t think Chapman is super different to USC, except for being a lot smaller of course. My parents went to USC, so don’t hate on me folks. It’s a great school, but I admit that it’s full of stereotypical people. Again though, there will be plenty of people at all these schools who don’t fit stereotypes.
One thing to note about So Cal is that smog can be a real problem with any colleges not right at the coast. Probably not too bad at UCSD, USD, and UCSB.
One other issue with So Cal universities and colleges is that there is a very car dependent culture. I think the San Diego and Santa Barbara colleges might fare better in terms of escaping campus. Most of the others are “landlocked.” Summers are hot and dry, and not all dorms have AC. It really does depend on the school, of course. I personally think being stuck in So Cal without a car would be a bit of a nightmare, but then again, driving anywhere in So Cal is a nightmare anyway.
Sorry to seem as though I’m bashing So Cal. It does have good weather, but weather isn’t everything. I think many people have a vision of palm trees swaying in the ocean breeze. They don’t think of driving, smog and strip malls.