Just for reference : Viewport Speed (realtime feedback) will benefit from Graphics card, CPU & RAM, Rendering only from CPU speed, really (or RAM if you're running out).
Definately not worth getting a Quaddro or Fire GL unless you plan to earn your living from the machine. For a gaming card, definately go for an NVidia, especially for Maya, the drivers are much better for 3D apps.
2 Gig ram will be handy. If she plans to do much animation, particularly character animation then it's worth getting at least a mid-range graphics card for closer to realtime playback speed.
I agree entirely re monitor, get the biggest decent quality you can afford. If you have the cash & space, a 2nd monitor will help a lot. You can put all your palettes / toolbars / dialogues / keyframes on there. A cheapo tft or old CRT will do fine for the 2nd monitor.
Finally, dual core is highly desirable here, better a cheapo dual core than a top-end single core for 3d work.