Martha's Mother was a minor character in An All Dogs Christmas Carol. She is the mother of Martha as shown in the present scenes Sasha La Fleur shows to Carface. She comes in when Timmy mistakenly breaks a plate of cookies in front of the fireplace trying to get a bone from his stocking; however, to Carface's surprise, she doesn't eject him when he admits to his own doing (though Martha claims she did it after thinking she heard Santa coming).
She does talk, but her voice actress is unknown.