According to the dating up to now accepted by the majority of Czech authors, Božena Němcová was born in 1820 as Barbara Pankl (or Barbora Panklová according to the usual Czech name-giving for women) in Vienna as a daughter of Johann Pankl from Lower Austria and Teresie Novotná, a maid of Bohemian origin.

In her childhood she lived near the small town of Ratibořice, where her grandmother Magdalena Novotná played an important part in her life.

Some authors question the birthdate (the preserved documents differ) and the real origin of Božena Němcová.

According to one hypothesis, Němcová could have been born three to four years earlier than previously thought, and been an illegitimate daughter of Wilhelmine, Duchess of Sagan (1781–1839).

In 1816 an illegitimate daughter was born to Wilhelmine's younger sister, Dorothée de Talleyrand-Périgord, and Count Karl Johann of Clam-Martinic (1792–1840) in Bourbon-l'Archambault (a French spa).