deffinitly get a good power supply and a decent video card (don’t really need top of the line unless she’s getting into very large/detailed scenes). a geforce 7900 or the ATi listed above should work great. I know that 3ds has optional nvidia shader packages you can use to view them in real time… may want to think about that/do some research before picking a brand to go with.
I’d also recomend getting the fastest processor that she can afford. It will help greatly with rendering times (biggest PITA with maya/3dsmax/ect) not to mention, if maya supports dual core… well, it should be a pretty dramatic improvement in speed.
oh, don’t skimp on memory either… go big (same with the hard drive… a 500gb drive should do the trick for a while)
all else, penny pinch on and you should be able to build one within budget. If need be, throw in some old junk parts and upgrade when the money is around 