Look at her Device Manager and see if there are and ?s next to devices. If not, then her USB ports may be fried. This can happen if USB devices are removed without safely stopping the port (which can be done by clicking on the green arrow on the taskbar and selecting which port to stop). I've had this happen to me and it's wicked annoying.

I've blown out the integrated USB ports on one of my mobos as well (heard some kind of electrical click or pop and they were gone). I just disabled them in the BIOS and plugged in a new USB ports card. May be a chance to upgrade her USB to high speed USB 2.0 if the mobo in question lacked that and her OS supports it. I look for a USB card with the NEC chip on it. If she has front-panel USB jacks, also look for a card that offers pins on the internal port(s) (some only have the external type jacks on them for the internal port(s)) - the cards usually have both internal and external ports on them. The last one I bought I got off eBay for under $10. shipped. Of course one can buy from a more reputable online reseller if s/he is more risk-averse... You can also get USB cards with other types of I/O ports on them too like Firewire or SATA/eSATA or PATA and add another desired feature or two with one stone. So don't look at it as a loss, see it as an opportunity... ;-)
 
.bh.

If all of the other post's dont work go in to your BIOS and check if the USB is enabled