Grimes was born in Lynn, Massachusetts, the daughter of Eola Willard (née Niles), a naturalist and spiritualist, and Luther Nichols Grimes, an innkeeper, country-club manager, and farmer [REF].
She attended high school at the then all-girls school, Beaver Country Day School, and Stephens College, and then studied acting at New York City's Neighborhood Playhouse [REF].