baby of the family vs preteen

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. 

preteen

noun
  • A child between approximately 10 and 12 years of age, at the onset of adolescence. 

adj
  • Of, relating to, or designed for, or being children between the ages of approximately 10 and 12. 

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