My fiance', a widow, is wondering if there is a word that refers to a deceased spouse's relatives?
Greetings, and good evening all,
My fiance's deceased husband's mother, lives with her, as she did while the husband/son was living.
My fiance' feels uncomfortable introducing her as ,"My deceased husband's mother", which is exactally who she is, but my fiance' feels uncomfortable with that verbage.
As she introduces me to her kid's relatives, she feels "odd, uneasy, or uncomfortable explaining to me that it is her (insert the missing term for deceased husband's relative, here).

So does ANYBODY know if such a term, or reference exists?