The movie interviews at least a dozen stutterers so she can definitely see different people who all stutter. Somebody commented a documentary about stuttering teens, that might also be interesting. But yeah it's important that she knows she's not the only one. Maybe go with her to a local support group once or twice if you have one in your area. Meeting and interacting with others like you can have a great impact. We had one boy and her mother join us a couple of times, once even making a small presentation about their cat, really wholesome.