I was cautioned not to buy a mac when I was an architecture student, because I would need to run Autocad. I decided I didn't need to give up my mac over one program, and so I got VPC. It's not the best solution, and I have ended up working on alternate CAD software as often as possible, but sometimes collaborative projects required Autocad. So I would run it on VPC. Like I said, not wonderful, but workable. VPC won't support dual monitors, and it won't print via my airport, but those are minor details, since 95%+ of what I do I can use the mac or pc equally. So I put up with a little inconvience with windows software to be able to be dual-platform. And believe me, my powerbook ended up saving many of my pc-using friends behinds when they would run into trouble connecting to a projector, or some other strange malfunction that always seemed to occur when it was presentation time.
So, long story short, if she will be using that specific peice of software a whole lot, or if there is absolutely no other possible alternative, maybe she does need a pc. But she will be in college, and all her friends will have them, so if she has VPC she might be ok. Kind of a judgement call, but any 'book from apple will play nice on the network, and will be less susceptible to any virus floating around as bonuses.