Blanca's childhood was marked by the third Carlist War (1872–1876) in which her father tried, unsuccessfully, to gain the throne of Spain by force. To be near the Spanish border Margherita moved with her children to Pau. For a time in 1875, Blanca lived in Elizondo, Navarre at the court established by her father. After the war ended badly, crushing Don Carlos' hopes of taking the throne of Spain, the family lived mostly in the Parisian district of Passy. In 1881 they were expelled from France due to Carlos's political activities. By then Blanca's parents had drifted apart. Her father went to live in his palace in Venice, while her mother retired to Tenuata Reale, an estate in Viareggio, Italy inherited in 1879 from Blanca's great-grandmother, Duchess Maria Teresa of Parma. Blanca and her siblings divided their time between their parents. In 1881 Blanca and her sisters entered the Sacre Coeur, a Catholic school run by nuns in Florence. Blanca played the mandolin and was very fond of horses. In 1883, upon finishing her schooling, she visited Spain incognito with her parents' permission. At her return she was officially introduced to the court in Vienna.
