Angela Pleasant got a call that she died

How is this situation possible?  I was playing the Pleasant family and Angela got a call from the Reaper saying they were sorry for her loss of her friend.  When I looked in her relationship bar the only deceased sim on the list was HER.  I mean somehow there was a second version of her running around in the game and then it had died.  Now the living one is very sad.   I can't invite the other one over on the phone or computer and nobody else in the family apparently ever ran into this doppleganger so they have no idea why she is so sad.  The Sims is such a weird game (although I'm sure this kind of thing is just a glitch and not intended to happen).  I hope in a couple of days she'll get over this "death"...never liked the whole grief scenario they put in the game.