What would you do, a friend asked the artist C. Finley, if you could curate the Whitney Biennial? Easy, Ms. Finley replied: It would be all women. “The Whitney Houston Biennial!” her friend announced.

That was in 2014. Ms. Finley laughed, and then she got to work — from that throwaway line, a festival was born. Now in its third edition, the Every Woman Biennial is the most expansive and ambitious yet. (Ms. Finley only recently changed its name from the Whitney Houston Biennial, for ease of fund-raising and after a polite but firm letter from the Houston family.) Opening Sunday, it features the work of over 600 women and gender-nonbinary artists — nine times the number of people in the actual Whitney Biennial that it is designed to run alongside. Ms. Finley’s exhibition will also include a female-centric film festival and, for the first time, will pop up in Los Angeles, with new artists, next month.

It came together on a shoestring, with donations and a network of volunteers, most of them female artists who brought their power tools and multimedia know-how to two downtown spaces. This week, they were completing the installation of pieces in materials ranging from textiles to video, driftwood to Flamin’ Hot Cheetos.