Gardiner worked with Curtis and Waititi to produce Tama Tū, Eagle vs Shark and the highly successful Boy, which set a new record for the highest grossing New Zealand film.

[2] Mokopuna was inspired by Gardiner's childhood as Māori girl living in Wadestown, Wellington, which had a very small Maori population.

[4] In 2017, Gardiner joined a team of women directors and writers to create the feature film Waru, which focuses on child abuse in New Zealand.

[2] Gardiner wrote and directed the segment titled "Mihi," which focused on the life of a single mother struggling to make end's meet.

[7] In 2023, Gardiner worked as an executive producer on the feature film Red, White & Brass, a Comedy Drama inspired by a true story of a Tongan super fan's attempt to get tickets to the Tonga vs. France Rugby World Cup.

[7] In the making of Cousins, Briar Grace Smith states that she and Ainsley Gardiner worked best with a "flat hierarchy," in which neither filmmaker had more control or command than the other.