Heckart was born in Columbus, Ohio, the daughter of Esther Stark, who wed Leo Herbert (not the child's father) at her own mother's insistence so her child would not be born with the stigma of illegitimacy.
Heckart naceu en Columbus, Ohio, filla de Esther Stark, que casou con Leo Herbert (que non era o pai da nena) pola insistencia da súa nai para que a filla non tivese o estigma de ilexítima.