I didn't mean to be ungrateful. It's just that the first response is the very same advice that appears in several fitting posts. And it seems to suggest that we might not have done the most obvious things already, like checked for size and that the left foot is in the left boot. I am here because two bootfitters have been unable to offer help and I thought it was possible that others have had a similar experience and might have an insight. I understand that bootfitting off the internet is impossible; that's not really what I'm after. The biggest problem is that because it's an issue of gradual numbness, it's almost impossible to ascertain when it's better or worse. She doesn't feel any pain, nor, when it's in the boot, does she notice any tingling or numbness (because it's a generally inactive part of the foot for her). She can wiggle toes, her feet stay warm -- it's that sometimes when she takes off her boot she suddenly realizes that part of her foot is "dead".
I'm trying to ask her to be more aware of that part of the foot -- after all the outside, little toe area is where one should initiate the turn and so she should feel it. But she's not quite there technique wise and so it creeps up on her.
Anyway, as I said, any specific suggestions would at least give us some lead to focus on. I'm going to follow up on both of your ideas and see if I can assess her flexion and whether we can find some pressure. The other problem is that when it's numb she can't tell where there's pressure, so we need to wait until the feeling returns (she's only just now getting it back, a week after Vail).
I don't really expect a miracle here -- it's just that we're in pretty dark territory without much to go on. And standard advice has not helped.