Never read any of S.E. Hinton's stuff. I'm guessing you like her because you quoted her book. So to ask if she is a good writer would be foolish. I'm assuming she is, she seems to be very popular. I do know that the line in the book was based on a Robert Frost Poem called "Nothing Gold Can Stay":
Nature's first green is gold,
Her hardest hue to hold.
Her early leaf's a flower;
But only so an hour.
Then leaf subsides to leaf.
So Eden sank to grief,
So dawn goes down to day.
Nothing gold can stay.