Is It Bad to Be Close Friends with a Non-believer?

All the online articles seem to paint non-Christians one color: “All nonbelievers are evil, will lead you off the path, and you’ll end up with fifty piercings and in a bar because of them.” But this friend of mine is the sweetest, kindest, least judgmental person I have ever met - including my Christian acquaintances. She doesn’t drink or any of that. Is it a bad idea to keep being her friend?