My daughter's cats were nevr feral, but they're extremely shy with anyone other than daughter and her boyfriend/partner, because they're just not used to company. When we go over there, they go into hiding.
Banshee will sometimes find a spot that she deems to be a safe distance away and sit and watch us, but if you try to get near her, she runs to hide again. Okay, Banshee, at least we got to see you!
Pooka is even shyer, and we rarely get a glimpse of her. The only time I got a good look at her was last spring, when I was taking care of the cats while daughter and her partner were away for a few days. I went over there every day, 4 days in a row, to scoop the litter box, add kibble to their bowls, and refill the drinking fountain as needed. Afterwards, I would hang around for a little while, usually sitting on the couch with my tablet, using my daughter's wifi to check in on DU or whatever.
Banshee got sufficiently used to me to get comfortable showing herself more, but Pooka stayed in hiding until the last day, when I looked up from my tablet to see her lying on the living room floor watching me. She was maybe 10 feet away, but she was in the same room with me AND in plain view, which were both firsts.
I still didn't get to touch either one of them, but I felt like I made a little bit of progress, just by being there as much as I was.
Of course, Carys having been feral is an additional challenge that I have no personal experience with, and I'm sure that makes it much harder. Still, it does sound like she has been gradually getting used to your friend's presence, and that sounds like a big milestone for her. Congratulations, Carys!
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