Mariann isn't an actress, but was picked to play a part in the film because of her distinct accent.
Mariann is a longtime caller of "The Howard Stern Show," which is how director Josh Safdie discovered her.
He wanted to cast her, regardless of her acting experience.
Mariann said at the end of a long shoot, wearing heavy makeup and a heavy costume, and under the bright lights, she fainted in front of the cast and crew.
Later, he saw Timothée Chalamet at a cast event, and he remembered that she had fainted and checked in on her.
She'll be in New York watching the Oscars this Sunday.
She explains her experience on set and meeting Timothée Chalamet with Mike Marza in the video player above.