I have two JRT's. A 3 yo female, Tater & a 2 yo male, Spud. Tell your friend to visit
www.terrier.com. This is the Jack Russell Terrier Club of America's web site and there is a wealth of info. This is an active breed and requires someone with an active life style. If your life style fits this breed you will have the time of your life! I'd rather spend time with my dogs than most people I know.
Good luck to your friend in finding the right dog for her.