I am going to disagree with pretty much everybody here.
If your daughter would be able to get an RTF copy of the school's dictionary, she could load that into Plover (after unchecking the other dictionaries), but only use it for homework (finger drills, practicing the new outlines and etc., with feedback via something like WordPad or Jarte: www.jarte.com).
On this end, I actually started using CAT software while I was in Theory (digitalCAT, for the curious). I hung out in the digitalCAT forums, read a lot, and pretty much taught myself how to use it -- mostly because I didn't like the way the "CAT" software they had installed on the computers in the labs worked (I think it was called "RealWrite" or something like that).
I will agree that Plover and Case are vastly different from each other, but when I switched from digitalCAT to Eclipse, I used what I learned in digitalCAT to get started ... and did the same thing with Case when I was taking a class in that.
With those caveats, chances are good your daughter will be just fine. Plus, she'll have a backup of her dictionaries should she decide to switch to a different CAT software later.
One thing I did in each of the CATs I learned was to set up a kind of "template" with all of my dictionaries selected and which writer I was using, and left a shortcut to that file on the desktop.
Each time I needed to use the program, all I had to do was double-click that shortcut, and my dictionaries and writer were automatically loaded, and that was that. When I was finished, I would do a "Save As," give the file another name, thereby leaving the "template" unmolested.
Great time saver!
Well. Good luck to your daughter! I'm sure she'll be fine. Otherwise, send her here to look around! Chances are good there are one or two Case experts available should she find herself stuck.