The Look of Love by Denise Cass Brookman (1960)

Candy was Kirk Stock's girl, and to be Kirk's girl was to be admired and respected--even envied.  For he was a letterman in football, president of the Senior Council, a good mixer, a good dancer and the most popular boy at Ryder High School.  Although they had similar tastes and backgrounds Candy found, oddly enough, that they had little to say to one another when they were alone.  All their friends shared the same comfortable standards and all of them conformed to the same safe, snug pattern that sometimes seemed to stifle Candy.

She had an indefinable yearning to find her own sense of values, and it was this quality that Joe Czierwotni recognized.  Joe's world was different.  Experience had made him realistic and truculent, but he was attracted to Candy even though common sense told him that he was remote from her life and therefore all wrong for her.  But the moment was right, and--feeling that she had everything, yet nothing--Candy was drawn to him regardless of her family's concern.

In this new junior novel about two people who are different--yet somehow the same--the author of The Tender Time introduces a sensitive, levelheaded young heroine who tries her own wings for the first time.  (from the inside flap)