The Descendants star didn't want to confront stage mums and daft dads while making her directorial debut, so she made a point of quizzing her potential child stars' folks.

"I was like, 'In addition to auditioning kids, can I audition and meet their parents too - because those are the people I have to deal with all the time!'" she tells WENN. "I had all these grand ideas about meeting their parents because if they were crazy I didn't know how I would do it."

Out of the process, the Jurassic World star landed "two amazing kids" and she admits she has now caught the directing bug.

"The film is called A Happening of Monumental Proportions and we're just finishing it now. It's amazing. Common is the star and he's incredible. Hopefully it will sell."

The film, about students at a school in Los Angeles who find themselves caught up in a plot of sex, lies and dead bodies, also features Alison Janney, Jennifer Garner, John Cho, Katie Holmes, and Bradley Whitford.

Written by Gary Lundy, the script for the project was a semi-finalist for the Nicholl Fellowship, and a finalist for the Screenwriters Lab at the Sundance Film Festival.

Greer will also return to the Planet of the Apes later this year (17), after reprising her role as Cornelia, the wife of ape army leader Caesar, for the project.