It can be any card really, just looking for the best one that her computer could handle. I didn't really look at what it says on Amazon so if it doesn't say, I think her psu is 300W and it does take pci-e cards.
What comes to mind is the ATI 4650/4670 should be worth looking at but I'm going to leave this for someone who knows this part of the market better then me.
You will probably benifit from upgrading the powersupply also and get a better card.