Page was the daughter of Mexican-American silent film star Don Alvarado (born José Ray Paige, in New Mexico) and Ann Boyar, the daughter of Russian Jewish immigrants.

Page, who initially thought the script to Casablanca was "old fashioned" and "clichéd", landed the role of Annina Brandel on her own and Warner reluctantly approved.

Page, along with Dooley Wilson and Humphrey Bogart, were the only American-born feature actors in the film.

She retired from acting after appearing in the first season of Disney's miniseries The Swamp Fox in 1959.

The year before, in her final film role, she played Prairie Flower, a Sioux Indian and mother of White Bull, played by Sal Mineo, in Tonka.