It's obviously a very personal choice and we are probably biased now.
I never quite understood her lack of interest for Cornell so I won't try to rationalize her decision.
We did visit schools again after admission. I suggest you go to some. HMC’s is next week I think.
HMC stood out as a good fit: strong math and CS education with a joint math/CS degree to pursue, a hard curriculum yet collaborative/supportive culture, interesting and motivated classmates, personal attention and accessible professors(I was talking through the academic buildings and saw most of the professors office open and many with professor working with student one on one), strong career path in both job placement and graduate study, part of 5 C and you can take classes of your interest from other schools and it is really a 6k student body socially.
So far I think most of these has worked out. My daughter is following the core curriculum (tested out a couple math ones), enjoying Putnam seminar/competition, taking private voice lesson/Choir from Scripps, American politics/linguistics from Pomona. She likes hanging out in some of her professors’ office. Working hard but enjoying it, she tells me it’s actually less demanding than high school, relatively. One thing I’d complain is that if you take CS42 in freshman Fall, they don’t allow freshman to continue with CS70 until sophomore Fall.
We also liked UCLA, even it’s a big school, but at least during the admission week, they were trying to make it personal. I liked the campus as well. For us, we never really liked UCB.
I guess a small LAC like HMC offers a good nurturing environment for kids like my daughter to transition into adulthood, vs a larger, less personal school. Later, she can still choose to go to UCB like for graduate study.