I think the car thing really, really depends on her school.
I went to a small school, in a tiny town. At the time, the nearest Wal-Mart was a half-hour drive away. This isn’t to say I spent a lot of time there, but just to give you a sense of what WASN’T around. Yes, getting around campus without a car was easy, but being able to do just about anything else (especially anything entertaining) required a car or mooching rides. I had a car most of the time I was there, but holy cow did it suck when my car was dead for any reason. It caused a lot of fights between me and my then boyfriend (but he was an ass anyway, so that’s another story). That said, in both incarnations of grad school, I really didn’t/don’t need a car, because public transportation makes everything workable.
I didn’t get an allowance of any sort, and I suspect that’s okay either way. I did get enough scholarships that I was basically paid to go to school. It wasn’t enough to keep me in pocket change, but it covered my truly needed expenses.
My parents tried to forbid me getting a job as a freshman. I got a job a month in anyway, and it was the right choice. On-campus only, as other people have said. In college towns like I lived in, schedulers are used to working around classes, but even some people I know had trouble with it. It also made me responsible for my own choices, though I’d been earning “real money” since I was 12 anyway, so I may not be the best candidate to say it’s fine. In my opinion, an allowance might be tending toward babying your daughter, but I’m not a parent and had a rather different college experience than most, so take it for what it’s worth.
As for credit hours, that really probably ought to be your daughter’s choice, and bear in mind she’ll have to run it by an advisor on campus. She may end up biting off more than she can chew, but so long as you’re supportive about her dropping classes as needed (until dropping to part-time), let her tackle some things. I rarely took fewer than 15 credits, and plenty of 18 credit semesters were fine. I have a friend who is still a touch peeved that she let herself get talked out of 18 credit semesters as a freshman (and did 21+ credit semesters with relative ease once or twice). She would have graduated a full year early if she’d followed her gut rather than her advisor’s advice, rather than a mere semester early. And she did very well in school. I usually say that it’s good for me she decided to stop after her bachelor’s or she’d be wiping the floor with me in grad school.
In the end, the thing that kept me most on the “straight and narrow” about my grades was never forgetting how much money hung on me getting it right. My mother sat me down just before I left and did the math with me about how much money I was getting through merit based scholarships. Then I slipped up enough my second semester to threaten (though not lose) them. I shaped up fast, though not completely I admit. But I never lost my scholarships, and that’s what mattered.
Finally, vet school is a complete bitch to get into by all accounts. If she really does seriously want to be a vet, all the above advice is true. She can’t afford a bad semester, she’ll need to work/volunteer in a vet office and lord only knows what else, and she’ll need extras. This, actually, may be the biggest reason to let her have the car and an allowance - so she can do the extra work involved in becoming a vet. I don’t speak from experience here, but I have watched so many friends try (and, unfortunately, usually fail) to get into vet school. It’s not an easy road at all, from what I’ve seen.
I guess if she does decide she wants to try to be a vet, maybe let her have the allowance and the car if she needs it to get to volunteer opportunities, but make it contingent on exceptional grades and actually doing volunteer work and so forth. Basically, facilitate her desire all you can, but the moment she behaves like it doesn’t matter to her then it doesn’t need to matter to you (vet school, I mean).
