Please, please, please tell her to get two! Guinea pigs are herding animals and do much better and are happier and healthier when they have at least another cage mate. Guinea pigs without a cage mate will get depressed and not be the same with another piggie it's own gender. I would search on Petfinder.com to see if they're any
GP's you can adopt from any local shelters. Good luck and tell you friend to never buy guinea pigs from pet stores since they are often mix-sexed and are unhealthy. (Most are from mills) If they're no guinea pigs on petfinder that you could adopt, try Craigslist... somebody might not be able to keep their piggie anymore etc. and may be giving it away for a cheap price. Please consider building your
GP a C&C...this site tells you where you can buy the cubes and choroplast and how to make the cage, what cage size you would need etc. Guinea pigs are fairly big rodents, therefore they need a lot of space to feel comfortable and do run around and popcorn.