The description of the book I am looking for is a young adult book, which I read in the 70’s (I was born in 1967).
The plot is a young girl living with her family in New York City who is obsessed with fashion. When her parents leave her in New York City alone when they go on vacation (which she is thrilled about) she stumbles into a Woody Allen set and believes she is going to be in the movie.
I read this, too, but barely remember it. I found a book online matches the description: The Rise and Fall of a Teenage Wacko, by Mary Anderson. https://www.fantasticfiction.com/a/mary-anderson/rise-and-fall-of-teen-age-wacko.htm
YES!
This is definitely it! How did you ever find it. I have been searching forever.Thank you so much!