I'm not sure what cities are close to Saint Louis, but tell her to go on petfinder.com and search for female guinea pigs in her town.
Here's a link
Also tell her to check out Craigslist.com in her city for guinea pigs. There are usually always guinea pigs for sale on there. Just keep checking. Try the local shelter where she lives to find piggies also. I'd recommend getting two, pigs love having friends.