The thing that she does not realize - success is perceived differently by people. Not everyone wants to be youtube "famous", have their own "small shop", buy endless supplies of the same grey jumpers,..
Many of us are way happier than she is, because we have people around us, with whom we can share our dreams, stories, go out for walks, and coffee. And we have people who root for us when we do things right, and help us get back on track when we fail. She may have "success" in her own terms, but she way from successful in terms of happiness.
So being jealous? Whatever helps you sleep at night Gabby.