housewife vs lady of the house

housewife

noun
  • A woman whose main employment is homemaking, maintaining the upkeep of her home and tending to household affairs; often, such a woman whose sole [unpaid] employment is homemaking. 

  • The wife of a householder; the mistress of a family; the female head of a household. 

  • A little case or bag for materials used in sewing, and for other articles of female work. 

lady of the house

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