Steve Trevor's secretary who befriends Diana. Describing her character, Davis said, "She's a woman in a man's world and so being heard and seen aren't the easiest things, but it kind of doesn't deter her", adding, "Etta is unapologetically herself and I think that that's the thing that has drawn me to her the most". When asked if she was previously familiar with the character, Davis responded, "No. I wasn't. It took me a while to know that I was auditioning for Etta because even when I found out it was Wonder Woman, I still had no idea what the role was. It took a little while then I Googled the character". On Etta Candy's relationship with Steve Trevor, Davis said, "One of the great things that Etta gets to work with Steve Trevor is because Steve is not your typical man, in that he does entrust her with things that in 1918 probably wouldn't have been entrusted to a secretary of somebody who is quite important", further explaining, "So I think that [Trevor] needs her just as much as she needs that because now she's been given responsibility that she wouldn't have normally be given before, and equally he has somebody who could probably fly under the radar a bit. So he can trust the person who no one's really looking at".
The Pre-Crisis version of the invisible plane was a necessity because before Crisis on Infinite Earths rewrote Wonder Woman's history – along with the histories of many other heroes – Wonder Woman could not fly. She grew increasingly powerful during and after the Silver Age of Comic Books, acquiring the power to ride wind currents and imitate flight over short distances. This had limitations, however; for example, if there was no wind and the air was completely still she would be trapped on the ground or if dropped from a distance that she would helplessly fall out of control to the ground. Though this meant that she would rely on the invisible plane less frequently, she always had need of it.
Filming occurred outside the U.S. Capitol in Washington D.C. during mid-June. Other filming locations around DC included the Penn Quarter neighborhood, McPherson Square, the DAR Constitution Hall near the White House, the Museum of Natural History (Smithsonian), and the Lincoln Memorial. By mid-July, production in the United States was completed and moved to England. In August, filming on location took place in several places around London, including St. Andrew's Place, Regent's Park and the Royal College of Physicians. Between September and October 2018, production also took place at Almería, in Andalusia, southern Spain, as well as Fuerteventura and Tenerife in the Canary Islands.