Vangsness was born in Pasadena, California, daughter of Errol Leroy Vangsness, of Norwegian descent, and wife Barbara Mary (née Marconi), of Italian descent. She was raised in Porterville, California, and later moved to Cerritos, California.
Errol Leroy Vangsness and his wife Barbara Mary (née Marconi) had a daughter named Vangsness who was born in Pasadena, California. The family initially lived in Porterville, California, but later relocated to Cerritos, California.