I don't know about AutoCAD stuff, does that use OpenGL to display CAD stuff, or is it just drafting 2d line stuff?
If it's just 2D, I would say go for something like a Matrox G550 and use the extra $$$ to get a second monitor, dual monitor for graphic design and CAD work is GREAT!
But if she needs OpenGL... go for a Geforce 3.