I have read all of your posts, and re-read your OP, so I don't think I have missed this bit of information, have you ever met your new employee, eg at the initial interview
@outofofficeon? I feel a bit silly asking that question, as surely it is a given that an employer actually meets someone before they hire them, unless they are going to be employed in somewhere like Antarctica, while the main team are based at, say, King's College, Cambridge. If you didn't meet her, have you ever seen her over video?
I am only wondering because I am very close to someone who has massive Social Phobia who just could not meet new people without becoming so stressed that it made them ill beforehand. However, the person I am talking about could not have attended University to obtain a degree, the only way that they could have got a degree was through the Open University.
How much of your employee's background are you aware of OP? Do you know whether she lives alone, or with her birth family, or a partner, or a friend? If she doesn't have Social Phobia, or something similar, could she be embarrassed about the room behind her looking untidy, or for some other similar reason? I believe that a PP said to let her know that she could have sort of false background, made presumably for people who don't want their homes, or wherever, to be seen.
If you haven't ever seen her, then the scenarios for why she doesn't want to be seen could be many. Maybe she is vastly overweight, or thinks she is, or perhaps she has some sort of visible disability that unfortunately embarrasses her? Whatever the reason is, it does seem to be having a profound effect on her daily life, and I really feel for her.
You sound like an absolutely lovely employer OP, and I think this 'young' lady was very lucky when she found you. So I really wish that I had any advice about how you should continue from here, because as nice as you seem to be, I know you probably can't continue to employ someone if they can't, or won't, fit in with the rest of their work colleagues.
I haven't read all of the other posts on here, but I would be very surprised if you haven't already had some great advice from other Mumsnetters. 💐