Her Majesty vs queen mother

Her Majesty

pron
  • A title of respect used when referring to a queen. 

  • A sarcastic way of referring to any female who is (or appears) pompous or bossy. 

queen mother

noun
  • A widowed queen consort (a queen dowager) whose son or daughter from that marriage is the reigning monarch. 

How often have the words Her Majesty and queen mother occurred in a corpus of books? (source: Google Ngram Viewer )