How interesting about your sister! I can see how that would cause anxiety.

When I was in my twenties, I used to meditate a lot. It so happened as I meditated more and more that I was able to know what people were going to say before they said it. Example- One day at work I was sitting there working and suddenly I "knew" Vicki sitting behind me would start talking about the old Mary Tyler Moore show that used to be on TV. About a minute later, Vicki started talking and asked if anyone remembered the old Mary Tyler Moore Show. That was one of hundreds of examples that happened to me and it really shakes you. I was anxious and wanted this to stop so I stopped meditating and eventually those experiences stopped, too. Years later I learned that experiences like that are OK. It's just a side effect from the meditation and you're not going crazy, you're just opening up your chakras.

Tell your sister that I "get it" and she's OK. It happens to others, too.