Modern art, commercialism and child development collide in the documentary My Kid Could Paint That, screening this Saturday at the Katharine Cornell Theatre in the Martha’s Vineyard Film Society series.

Parents all watch and admire as their offspring first pick up a paint brush; most encourage their children to express themselves through art. But what happens when it turns out that a child might be a true prodigy — with parents willing to go to great lengths to convince the world of her genius?

In 2004, four-year-old Marla Olmstead of Binghamton, N.Y., took the art world by storm. After an article about her by a Binghamton reporter, The New York Times picked up on the story and helped create a child celebrity. Soon Marla Olmstead pieces were being sold for five-figure sums, and more. But then the television show 60 Minutes investigated and raised doubts about who was creating the artwork. Marla’s father, Mark, it turned out, is a gifted painter in his own right: might he have used Marla as a gimmick to break into the closed world of abstract art?

Overnight, Marla went from child star to declared fraud. But then she climbed right back up.

Amir Bar-Lev, director of My Kid Could Paint That, spent thousands of hours with the Olmsteads, His nuanced documentary, rated PG-13 and lasting 83 minutes, screens at 7:30 p.m. on Saturday at the Katharine Cornell Theatre in Vineyard Haven. Admission is is $8 and $5 for film society members. .