At 15, she started taking acting classes as a hobby to help overcome her 'shyness'.
Born and raised in New York. Her father, Thomas Garner, is an art teacher, originally from Ohio. Her mother, Tami Gingold, who is originally from Israel, is a therapist who was 'a famous comedian in Israel 30 years ago'.
Her mother, Tami Gingold, was a therapist and led a successful comedy career in Israel. Her father, Thomas Garner, was a painter and art teacher. Her sister, Anna, is a writer, artist, and producer.
She began taking acting lessons at the age of fifteen to overcome shyness. By the time she was seventeen, she had made her theatrical debut in the 2011 film Martha Marcy May Marlene.
Garner married singer Mark Foster, lead vocalist of Foster the People, in a December 2019.
Counts fellow actress Juno Temple as a close friend.
She earned her first starring role in the 2012 film Electrick Children.
She was cast alongside Zoey Deutch and Nicholas Braun in the 2016 comedy Good Kids.