|Louis Martin, Thérèse's father|
Thérèse's parents were holy, and wanted to give their entire lives to God. When they were younger, each of them had pursued the religious life, going so far as to apply to particular orders. Thérèse's mother, Zélie Guérin, applied to the Sisters of Charity of St. Vincent de Paul, while Thérèse's father, Louis Martin, applied to the Augustinian Monastery of the Great St Bernard. Both of them were rejected.
Zélie ended up becoming a lacemaker, while Louis became a watchmaker. Externally, this would seem to be something of a failure -- making lace and watches seems to have little to do with bringing glory to God, particularly in comparison with being a monk or a nun. Eventually, in 1858, Zélie and Louis met, fell in love, and three months later, married. At first, the two did not consummate the marriage - they wanted a spiritual marriage, living as brother and sister in a non-sexual relationship. After nine months, at the insistence of their confessor, the marriage was finally consummated.
In all, Louis and Zélie gave birth to nine children. Three of them died in infancy, and a fourth at the age of five. This left five children, all daughters: Marie, Pauline, Léonie, Céline, and the baby of the family, Thérèse. Prior to Thérèse's fourth birthday, her mother, Zélie, died of breast cancer, leaving Louis to raise the four girls. Each of them would go on to become nuns, and Thérèse, of course, went on to become the 33rd Doctor of the Church.
I think that the lives of Zélie and Louis help illustrate the mysterious way in which marriage and family are intertwined with celibacy and the religious life. The Catechism remarks on this in CCC 1620, which says:
Marriage is an amazing good, for the benefit of man, and for the glory of God. Celibacy for the sake of the Kingdom of God is an even superior good. But the greatest good is to do the will of God. For Louis and Zélie, this meant the married life. And through marriage and family, they accomplished much more than they likely would have as a simple nun and monk: together, they gave the world one of the greatest Saints of all time.
St. Thérèse of LisieuxBoth the sacrament of Matrimony and virginity for the Kingdom of God come from the Lord himself. It is he who gives them meaning and grants them the grace which is indispensable for living them out in conformity with his will. (Cf. Mt 19:3-12.) Esteem of virginity for the sake of the kingdom (Cf. LG 42; PC 12; OT 10.) and the Christian understanding of marriage are inseparable, and they reinforce each other:
“Whoever denigrates marriage also diminishes the glory of virginity. Whoever praises it makes virginity more admirable and resplendent. What appears good only in comparison with evil would not be truly good. The most excellent good is something even better than what is admitted to be good.” (St. John Chrysostom, De virg. 10,1:PG 48,540; Cf. John Paul II, FC 16.)
In discussing vocations, it's helpful to speak of the primary vocation and secondary vocation. The primary vocation is simple. You're called to be a Saint. Doesn't matter who you are, what your strengths or weaknesses are, or what your state of life is. God designed you to know, love, and serve Him, and to enjoy eternity with Him. That's what sanctity is. The secondary vocation, whether you're called to be a priest, monk, nun, father, mother, or a single man or woman, flows out of the first: it's the way that you're called to live out your primary vocation. Louis and Zélie didn't end up with the secondary vocations that either of them anticipated for themselves. But by staying loyal to God throughout, they lived out inspiring and holy lives, and raised a saintly family. The Church recognized this, not only in canonizing their daughter, and declaring her a Doctor of the Church, but in beatifying Louis and Zélie themselves.