I’m so sorry to hear that your daughter is having a hard time making friends right now. I agree with the comments above that the B/W thinking is very much related to her age. I have three teenage daughters and each had a different experience navigating friendships in elementary school. One day they have a BFF for life and the next day they are sworn enemies! I liken it to going on a roller coaster when you were told it was a Merry-Go_Round! I would want to rush to their aide and get to the bottom of the issue and then they would work it out on their own.
I would email her teacher about how she is doing. Sometimes our kids paint a much different picture of what’s going on at school. By emailing their teachers, I have been pleasantly surprised to find out that my girls were doing just fine (and saving all the drama for me!)
I would encourage you to keep a positive frame of mind. I am not discounting any sad feelings your daughter might have, but it truly might not be as bad as you think. I would also encourage her that to earn a friend we have to be a friend. Maybe someone in her class is needing a friend as well? Reach out to other Moms for park play dates (less pressure than going to each other’s houses)and keep her busy! The black and white thinking is hard, but it really is how most kids think at that age. (BTW – I have ADHD so does my youngest (age 12)