Idk, man. I think a supportive mom would've sat her daughter down to have some unconfortable conversations before sending her away unprepared (to college, no less).
She seems supportive of her daughter "only living once" because she only knows a tenth of the story.
Parents aren't friends. They shouIdn't be "yes men"/"yass queen slay".
"But she says she lectured her when she first heard about it". Definitely not as much as she would have if she knew what was up. We can't say her apology comes from a desire to support when it can simply be ignorance.
Preventing you from breaking might feel harsher at the time but is more supportive than picking up your pieces (the ones they can see) and giving you some fluffy reassuring line they can't back up because they can't see the future.
And the "supportive" friend who pressured a clearly unpopular, lonely girl to go to such a place? Ended up not needing 24 hours to consider he made a mistake but she could have used a quicker realization.
She's an adult, it's ultimately all on her at the end of the night, but she needed more support than "it'll be fine".