You can read Fr. Albert Dolan's biography of Leonie Martin, God Made the Violet, Too: A Life of Leonie, Sister of St. Therese (Chicago: Carmelite Press, 1948) online thanks to HathiTrust Digital Library. Fr. Albert Dolan, who founded the Society of the Little Flower, visited France and became acquainted with the sisters of St. Therese; he then spoke and wrote about them in the United States as he spread devotion to St. Therese. You may read the account of his visits with the sisters of St. Therese in his book The Intimate Life of Saint Therese Portrayed by Those Who Knew Her.