Estelle Beardly was Jasper Beardly's wife. It's only mentioned that she had died and Jasper cremated her. Given that she was laid to rest when Reverend Lovejoy was uncertified, it is assumed that she died shortly before "A Milhouse Divided".
Appearances
Episode – "Lady Bouvier's Lover" (Possibly)
Episode – "Wedding for Disaster" (Mentioned)- Episode – "Replaceable You" (Mentioned)