So just unfollow her. It sounds like you have some major issues with her personally anyway so how is this a failure by the platform and not just you subjecting yourself to a negative situation?
The problem is that Facebook is convinced that I, a British citizen living in Berlin, want to see “Bernie Sanders Dank Memes” (or whatever it was, there are many) even though I’ve clicked on the button labeled “don’t show me ‘Bernie Sanders Dank Memes’“.
The “even though I’ve clicked on the button” is especially egregious, in this context.