The as-yet-untitled film was just announced on June 24, so it's a long way off from entering production, let alone having a release date. The script likely isn't even written yet.
Currently, Dunham is in post-production (via IMDb) on an adaptation of the children's historical novel "Catherine, Called Birdy" she wrote and directed. That movie has a great cast including "Game of Thrones" and "The Last of Us" star Bella Ramsey as the title character, "Game of Thrones" and "1917" star Dean-Charles Chapman, and the Hot Priest from "Fleabag," Andrew Scott. Therefore, meaningful work on the Polly Pocket movie will have to wait until after "Catherine, Called Birdy" is completed.
Dunham also wrote and directed an indie film called "Sharp Stick" that's in the can and seeking a distributor, according to Variety. Little is known about "Sharp Stick" –- which was shot in secret -– aside from the cast, which includes "Zola" star Taylour Paige, indie film icon Jennifer Jason Leigh, and "The Walking Dead" alum Jon Bernthal.
So, to make a long story short, Dunham is busy, and "Polly Pocket" will probably have to wait until she can devote some time to it.
