Sabrina (Audrey Hepburn)’s Timeline and Summary

Sabrina, a chauffeur's daughter on Long Island, is in love with one of her father's employers, the wealthy playboy David Larrabee.
In despair because he doesn't know she exists, she tries to kill herself with carbon monoxide poisoning.
She's saved by Linus Larrabee, David's sober, workaholic older brother.
Sabrina goes to Paris to learn cooking and try to forget David.
In cooking school, she meets Baron St. Fontanel, who takes her under his wing and teaches her to be cultured and sophisticated.
Sabrina returns to Long Island a chic young woman, and she wows David, who falls in love with her straight away (as you do in Hollywood movies.)
Linus wants David to marry Elizabeth Tyson to seal a business deal; he's upset that Sabrina and David have fallen in love.
He arranges for David to injure himself by sitting on champagne glasses; then he romances Sabrina himself.
Sabrina does fall in love with Linus. Linus, to his surprise, falls in love right back.
Linus originally intended to put Sabrina on a boat to Paris, claim he was going, back out at the last moment, and with her out of the way, push through with David's wedding and business deal.
But, he changes his mind and urges David to go with Sabrina to Paris.
David, though, knows Sabrina is now in love with Linus, and he insists Linus go with her to Paris.
So Linus does. Happy ending.