Fernández Solar received her education in a college managed by French nuns from the Sacred Heart order, and she remained there from 1907 until 1918. In 1914, she decided to consecrate herself to the Lord and become a Discalced Carmelite. On 8 December 1915, she made a vow to remain chaste and she renewed it on a regular basis. Fernández Solar was pious in character, but could also be stubborn and vain; she also lost her temper on some occasions. On one particular occasion, her sister Rebeca grew so fed up with Juana that she hit her while the red-faced Juana grabbed her with anger but stopped and kissed her cheek. Rebeca was confused and unsure but chased her off and said: "Get out of here! You have given me the kiss of Judas!" Juana was hospitalized in 1913 for acute appendicitis. In her childhood, she also liked singing and dancing and played croquet and tennis. She was an able swimmer and could play the piano and harmonium. In 1916, she made a retreat for the Spiritual Exercises.