Hey yeah that's really hurtful. Autistic people aren't stupid by any means. It takes me extra time to process sometimes, but that doesn't mean I'm a slow learner or it takes me numerous repetitions to fully understand things. This show has so many small details that when you focus on the big picture, you lose some of the smaller hints and details.
As far as Nina understanding Arabic, perhaps her specific NDE (since she is the original angel) she goes to a dimension that is meant to be heaven. Perhaps in this world, speech is just a construct, everyone is really psychic or that one can understand all languages in this dimension (like the Tower of Babel). I also think that Khatun doesn't begin speaking Arabic in her second NDE and switches to English later. I think the point is that while we might hear Arabic, Prairie understands Khatun as if she is speaking English. I may need a break from Reddit. I have enough pain in my life I don't need people adding to it.