I’m going to cast a vote strongly in favor of Mills College/Oakland.
Although it doesn’t exactly have a world-wide reputation, Mills is pretty highly respected by those who are familiar with US liberal-arts colleges. It’s academically rigorous, and has a beautiful campus in a nice, safe part of the Oakland hills. The student body is diverse (except for the obvious absence of Y-chromosomes amongst the undergraduates), and although the college has a feminist/liberal slant, the Mills graduates that I have known personally have been free-thinkers and not brainwashed. Your namesake would have been very happy with a Mills grad (and Eve Kendall might well have been one!). There’s a list of alumnae at the Wikipedia page here.
[Barbara Lee, the current US Representative for Oakland and Mills alumna, was briefly famous back in 2001 for being the only member of Congress to vote against granting GWB the broadened powers he subsequently acquired post-9/11. She considered it the role of Congress to determine which countries, if any, should be invaded. Interview here. I, for one, agree with her, and wasn’t a bit surprised to learn that she was a Mills alumna.]
Your wife’s niece wouldn’t need a car at Mills (I would recommend that she live on campus, especially if only there for three months). There are numerous social and cultural activities at Mills itself, but it’s also easy to get to Oakland (~15 minutes) and San Francisco or Berkeley (30-45 minutes in each case) by a bus / train combination (e.g. AC Transit bus #57 to BART, running every 12/15 minutes at most times).
As you can tell from the responses in this thread, mention of Oakland can be quite polarizing. It’s true that the city has a high crime rate in certain areas, but those areas are easily avoided by a student at Mills (especially if she lives on campus). By far the majority of violent crime is within the same demographic group in certain well-defined areas, so although Oakland can be a very dangerous place if you’re living in the bad areas (unfortunately there’s a fair amount of “collateral damage” of innocent victims amongst the gang turf wars), tens of thousands of Oaklanders live happy productive lives without fear of random violence. I’m sure that any orientation at Mills (especially for foreign students) would delineate the safe and unsafe areas. I know that the Bay Area Dopers would be able to put a pretty good map together as well…
Oakland suffers from a largely-undeserved bad reputation – reinforced by those who misuderstand Gertrude Stein’s line of “There’s No There There” (she was referring to a return to her childhood home, which had been knocked down, and not to anything about Oakland per se). It also lives in the shadow of the world-class reputation of San Francisco, just across the Bay; if a city with Oakland’s cultural life were not right next to SF and Berkeley, it would be justly famous in its own right. There’s a thriving arts and music scene. The Oakland Museum is fascinating. The climate is excellent (the air comes in fresh off the Pacific just like in SF, but Oakland gets much less fog and more sun). There’s a lot of easily-accessible hikeable parkland in the Oakland hills, and the views are spectacular. It would truly be an experience to treasure for her, and she’d undoubtedly make good lifelong friends at Mills.
I’ve never lived in Pensacola, but good friends of mine have, and couldn’t wait to leave. It’s largely a military town, and public transit is almost non-existent so she’d go nuts without a car. As was written above, auto-racing and football are the main live cultural options.
There’s no question that Mills would be more expensive; not just because of the cost of living, but because there’s so much more to do. However, a great deal of the joy of living in the Bay Area (wonderful, interesting and smart people, and superb natural spaces) doesn’t carry a pricetag.