How do you convince your girlfriend that a "Psychic" should not decide a relationship?

My girlfriend went to a psychic because she had some other areas of life that were bothering her and wanted some “insight” for, ( I was not there.) her psychic did a short reading on me said that we were great together and great lovers but only saw us as lovers (basically nothing long term.) We have been together almost 2 years now and things have been great! But since she had this “reading” she has been acting a bit more distant and aloof. Like she maybe creating some issue where there wasent one simply because the “psychc” said there was one. There is absolutely nothing wrong with our relationship otherwise. We get along great on ALL aspects. We very rarely argue and when we do its resloved quickly and back to being happy again. I can trully see us as getting married a bit down the line and having a wonderfull life together. I just dont know how to get rid of this ridiculous doubt that I see in her eyes now. Because once its there… well its there, and will forever cloud her judgement from now on. How do I handle that doubt?