My first impulse was that the "Who cares?" attitude was that of a troll, but after thinking about it a bit I realized how Windows-centric my University had been (RPI Computer Engineering - Class of 2005). Via a financial aid package I got a free (at the time) top of the line laptop which happily ran Windows during my time there. Then there was the Vorhees Computing Center which was divided up between Windows on the left (where you'd go to print stuff) and UNIX on the right (which was mostly ignored because it was fairly ancient).
Anyway... point is that AFTER college all of my computers have been loaded with Linux and my "work" computers continue to be predominantly Windows. This is a fact of life.
If you have the luxury, I'd put in the following recommendation: making sure she's got easy access to both Linux and Windows. Because I'll say this, knowing what Linux does well and learning what Windows can handle satisfactorily will give her an advantage over the people on campus who only know one way of doing things.
If easily/convenient computer labs on campus offer Windows desktops, send her to school with a Linux laptop. If not... is sending a student to campus with two laptops or a desktop+laptop really that hard to imagine?
And when she asks you how to configure Samba, Cygwin, Wine, Apache, and remote terminals... be prepared with the answers.