Did you uncheck the "Let Windows detect plug-and-play printers" during that set of instructions before? No guarantee that it would work (as USB is pretty-much always plug-and-play).
I think if you try to install different drivers for the printer, Winders may do an end-run around the different drivers as soon as you plug the printer in.
But, there are ways to try to install a different driver for the printer.
Let's assume you have the printer connected and it has gone through an installation cycle.
Again, this is for Windows2000 but should be similar for you:
Do Start -> Settings -> Printers
Click with the Right mouse button on the HP printer icon.
Select "Properties"
Click on the Advanced tab
Click on the "New Driver..." button.
Next
Select HP on the left, and a DeskJet driver on the right that you want to try.
Continue with the steps.
With luck, something will stick and work properly. If you've already effectively done this, then, well... :-(
Another thing that might be worth trying is to install ghostscript and print through it (e.g. have her print to a PostScript file and then use ghostscript to dump it to a printer). It can be a hassle to set up, but might be a software solution.
ghostscript is a PS rasterizer with lots of nice features - http://pages.cs.wisc.edu/~ghost/
gsview is a Windows graphical front-end for ghostscript - http://pages.cs.wisc.edu/~ghost/gsview/
Both are free.
I hope this helps a little. I fear, though, that there isn't a real, non-kludgey, solution other than perhaps running Winders in a virtual machine on a Mac. :-( Unless you're willing to try a different physical printer. (I've had good luck with Canon inkjets on OSX and Winders.)
Good luck.
Cheers,
Scott.