On the morning of April 9, 1888, after the 7:00 a.m. Mass, St. Therese was accompanied to the enclosure door by her father and her sisters Leonie and Celine, as well as other relatives. For a few moments all five daughters were near each other, although two (Pauline and Marie) remained inside the enclosure, where they were already living as Carmelites. Later that same day Celine wrote to the Carmelites to tell them how generously Louis was accepting the loss of his little Therese. His oldest daughter and his favorite, Marie, wrote to him at once to praise his generosity. "What Celine tells us is worthy of you." She ended her letter, "Our Mother [the prioress, Mother Marie de Gonzague] couldn’t help crying as she read Céline’s account. Ah! What a remarkable father you are!!"
(Sister Marie of the Sacred Heart to her father, Louis Martin, April 9, 1888. Read the whole letter on the Web site of the Archives of the Lisieux Carmel. Photos courtesy of the Web Site of the Archives of the Lisieux Carmel).
François-Julien Nogrix, 1823-1898
The next day Louis wrote to his friends the Nogrix family to announce Therese's entrance.
Thérèse, my little Queen, entered Carmel yesterday! God alone could demand such a sacrifice, but He’s helping me so powerfully that through my tears, my heart abounds with joy.
One who loves you,
Louis Martin.
Madame Nogrix (baptismal name unknown)
François-Julien Nogrix was an intimate friend of Louis Martin's from Louis's time in Brittany, where Louis studied watchmaking. In 1883, when Louis was 59 or 60 years old and Therese was ten, M. Nogrix wrote to tell Louis that he had returned to the Church. Louis answered with a joyful letter in which he recalls the happy times they had together as young men. Read the letter here at the Web site of the Archives of the Carmel of Lisieux. 
The little daughter of M. and Mme. Nogrix; her baptismal name is unknown. She is photographed with her tricycle, as Therese was with her jumping rope
[Text of both letters from A Call To A Deeper Love: The Family Correspondence of the Parents of Saint Therese of the Child Jesus, 1863-1885 Staten Island, N.Y.: Society of St. Paul/Alba House, 2011].