Grandma Duck

[Juuso Paaso]

  Dear Don,
 
    In your Lo$-stories $crooge has two sisters, right? And I have understood
  that Grandma Duck is $crooges sister. But, in the Finnish translation the
  names of those duck-ladys are 'Matilda' and 'Hortensia, whil the Finnish
  translation of Grandma Duck's real name is 'Kaino-Vieno'. 
    So, could you tell me if one of those sisters really is Grandma Duck? Or
  if either one of them is, then could you tell me what is the relation of
  $crooge and Grandma?
 
    Yours,
         Juuso Paaso