I’m not exactly sure, but it was definitely longer than 40 hours. I know for a fact I had stationed her as a guard for a couple days ( I guess 4-5 ) in my base as I didn’t have armor for her at that point and then I’ve done some looting with her for a day or two.
But she died literally the same turn the mission failed. It was literally like this:
Mission ‘Finding Records’ failed.
Jane McNPC died!
Actually, this reminded me of something. I do recall her having a blue wound after a fight with some zeds, so I wanted to disinfect her but then when I was about to do that the wound mysteriously vanished. I thought she had disinfected it herself ( I assume NPCs do that ). But yeah, that wound was definitely gone, I’m 100% sure about that.