What does the mean when girl say good morning brother? ?

There is a friend of mine that refers me as her great friend! This morning she messaged me via internet chat room saying, “Good morning Brother” what could that mean? 

choko_canyon2021-02-05T09:23:50Z

Using the word "Brother" in that context is the same as calling you "friend", and she wants to make certain that you realize that you are ONLY friends, and nothing else. Do you think you can deal with that, despite the obvious fact that you have Asperger's?