preteen vs youngsome

preteen

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

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

youngsome

adj
  • Seemingly young in appearance, manner, or behaviour; youthful 

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