amma vs old lady

amma

noun
  • mother 

  • An abbess or spiritual mother, especially one of the Desert Mothers. 

old lady

noun
  • One's mother. 

  • The Bank of England, sometimes referred to as the “Old Lady of Threadneedle Street” or simply “The Old Lady”. 

  • A queen. 

  • An elderly woman. 

  • One's girlfriend, wife or significant other. 

How often have the words amma and old lady occurred in a corpus of books? (source: Google Ngram Viewer )