Both my female rescue cats are done, one of them, who I lost earlier this year, gave me one hell of a fright one evening. I could hear her yowling as if in pain and was out walking the streets in my nightie and jeans (with a coat over) calling her. My hearing isn't great but worked out roughly where she was, knocked on a door nearby in a panic and ended up me and these two young guys (who I think thought I was a bit of a nutter) traming round with torches in the large overgrown garden at the back of their house.
Finally found here and she was absolutely fine, turns out she was having a bit of fun! Awful noise they make though. So even though done, they can indulge!
Could she have got shut in somewhere? Especially if people have gone away for a Christmas break or not been out in sheds or such with festivities going on?