bahu vs paternal aunt

bahu

noun
  • A daughter-in-law or sister-in-law, especially one who lives with her husband's family when married. 

paternal aunt

noun
  • The wife of a sibling of someone’s father. 

  • A sister of someone’s father. 

How often have the words bahu and paternal aunt occurred in a corpus of books? (source: Google Ngram Viewer )