I've come across this 2001 short story called Unreliable Witness by Jo Walton, posted on the Strange Horizons site.
It's a 1st person account, nominally transcribed from tape, by a senile old lady in an old people's home who is visited by an Alien.
It's short, delightful, thought provoking, and ever so slightly emotional as most of us have family members in similar situations (minus the Alien, in most cases, I presume).
The full story can be read here, or listened to as a Podcast on Drabblecast.
