flowerbells, Wow you sound like a very dedicated friend to even write so many details about her. Sometimes people change and we have people in our lives for awhile and it was meant for a purpose. Sometimes our brains are wired differently and we have a hard time relating to different people. She and you sound like you have some similar interests but maybe the way each of you approach things is very different and this leads to further confusion with your friendship.

No one here can really tell you whether she has a personality disorder or not. I am not a mental health professional so the things that I picked up on were her ways at approaching things. You say that she is very scientific. There you go, scientists have a very methodical way at approaching things. I used to be married to one. He was very methodical and without very many expressed emotions. I was the opposite with depression and very much sentimental and into music and song writing.

I tried to do you justice with the limit of my scope. I hope this helps in some small way. Regards.