girl friend vs lovebird

girl friend

noun
  • A female friend, especially a woman's. 

lovebird

noun
  • One of the members of an openly affectionate couple. 

  • Any small parrot from one of the nine species within the genus Agapornis. Sometimes they are kept as cage birds and are noted for their affection towards each other. 

verb
  • To express romantic affection openly. 

How often have the words girl friend and lovebird occurred in a corpus of books? (source: Google Ngram Viewer )