I haven't added to this thread yet because I was deferring to those with more experience who are better informed than I am. By the way, I think they have all given very good advice. I just thought I would jump in because I didn't get the impression that "Survivor" was rejecting anyone's advice. She strikes me as the taking it on board and carefully considering the options that are available to her.
Now, as for a technique that can help bridge that gap, how about wakigatame. It is a very close technique where you stay in full control of uke. Also, you could try the back stretch where uke holds your wrists and you load them onto your back before leaning forwards. It would take the danger out of Koshinage for uke, while you could slowly desensitise yourself to the sensation. Just a thought.
I am not familiar with wakigatame, could you describe it? The back stretch is a good idea, we don't do those often, and I do also sit out of those, but I think that might be a good thing to work on for now. Thank you!