Trivia

Left the acting world in the '80s and became a registered nurse. She married a surgeon. They have no children.

The first actor to kill a Clint Eastwood character in a film: El engaño (1971).

Ferdin was one of many child actresses (including the late Dana Plato) to audition for the role of "Regan MacNeil" in El exorcista (1973). Linda Blair (13 days older than Ferdin) won the part.

An outspoken animal rights activist, in 1996 she quit her job as director of public relations for the Center for Animal Care and Control, a nonprofit organization under contract to the New York City Department of Health, claiming mismanagement by the agency.

On January 11, 2000, Ferdin, a vigorous animal activist, faced up to six months in jail after being found guilty of carrying an elephant bullhook at an August 1999 protest of circus training methods. A bullhook is a wooden rod with a sharp hook that is jabbed into sensitive areas of the elephant to keep it fearful and manageable. She received 30 days.

Ironically, as a staunch animal rights activist, her role opposite Clint Eastwood in El engaño (1971) was of a little girl who loved, protected and nursed animals, including a crow and, more famously in that movie, a turtle.

Was the first choice for the voice of Penny in Bernardo y Bianca (1977).

Was good friends with Peter Robbins.