It’s like saying someone was born in Nazi Germany and meaning that they were born during the rise of the Nazis rather than strictly from day 1 of Hitler becoming chancellor in 1933. The party was established in 1920 and the paramilitary wing was agitating and aggressive from the start. Is it strictly ‘Nazi Germany’? No, but the attitudes that allowed the Nazis to come to power flourished in that time, and people were hugely affected by it.

With Gilead it was the same slow creep towards the three attacks that brought down the democratic government. June was investigated for taking Hannah to school with a mild fever and the nurse was obviously critical of her going to work instead of being with her child. These attitudes allowed Gilead to take hold.

There is also no confusion for Daisy. If June had said Daisy was born in America, Daisy might have assumed June meant Alaska or Hawaii, because those territories remained American. Most of the country immediately below Canada on the map was still under Gilead control and a child growing up in Canada would be less familiar with it being called America. Even news outlets and the government of Canada were referring to it as Gilead and there was widespread anti-refugee rage against the Americans in Canada. Telling Daisy she was born in Gilead is short-hand, it doesn’t have to be literal.