Yesterday I wrote that Marshak was involved in early ST fan fiction and may have created slash. I did research on her. She was heavily involved with kraith. It is heavily Vulcan centric stories. Marshak got involved seems like midway and had Sarek adopt Kirk and be Spock's student. On other sites I found one description of Spock spanking Kirk for disobeying. Kraith seems to focus at least from wikipedia definition on the main object at the start how Star Trek's federation is Earth centric and Kirk pushes not just Earth centric ideas but white male. Kraith seems like it did impact Roddenberry, Spock's death and rebirth appears to have Kraith foundations. Marshak's slash was one of hurt/heal a precursor to the modern slash.