baby vs baby of the family

baby

noun
  • The lastborn of a family; the youngest sibling, irrespective of age. 

  • Unborn young; a fetus. 

  • A pet project or responsibility. 

  • An affectionate term for anything. 

  • A very young human, particularly from conception or birth to a couple of years old or until walking is fully mastered. 

  • A form of address to a person considered to be attractive. 

  • A concept or creation endeared by its creator. 

  • One who is new to an identity or community. 

  • A term of endearment used to refer to or address one's girlfriend, boyfriend or spouse. 

  • A person's romantic partner. 

  • Any very young animal, especially a vertebrate; many species have specific names for their babies, such as kittens for the babies of cats, puppies for the babies of dogs, and chicks for the babies of birds. See Category:Baby animals for more. 

  • A person who is immature, infantile or feeble. 

  • A person who is new to or inexperienced in something. 

adj
  • Like or pertaining to a baby, in size or youth; small, young. 

  • Picked when small and immature (as in baby corn, baby potatoes). 

  • Newest (overall, or in some group or state), most inexperienced. 

verb
  • To tend (something) with care; to be overly attentive to (something), fuss over. 

  • To coddle; to pamper somebody like an infant. 

baby of the family

noun
  • The youngest member of an immediate family. 

  • A member of an immediate family who behaves as, or is treated as though they were the youngest member of a family. 

  • An adult member of an immediate family who is treated by others in the family, especially the parents, as though they were a child. 

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