Personally, I think this particular mystery has been solved. The yearbook photo girl that was discussed at length earlier in this thread is extremely likely to be the girl in the fur coat, who for any number of legitimate reasons denied being that person when asked about it, decades later, by someone unknown to her, via an email.
If the two females are one and the same, then obviously the fur coat girl lived through her experiences. The mark around her mouth looks so much like tape had been there, possibly for some time, and then removed right before the pic was taken. And who knows? Maybe that did happen, and somehow or another the girl got away and continued living for decades to come. Or it could be that the image of a kidnap victim with duct tape on her mouth is so ubiquitous in our culture that I'm imagining a scenario that didn't actually happen. I would've sworn that fur coat girl's mouth had been covered with tape right before that photo was taken (and maybe it was). But I'm completely convinced CarlK identified her and found her, alive, nearly 50 years later. So if she did have an experience with Alcala that resulted in her mouth being taped and a photo being taken of her but her not being killed, then she sure isn't talking about it.