I had a father and mother, who were devout and feared God. Our Lord also helped me with His grace. All this would have been enough to make me good, if I had not been so wicked. My father was very much given to the reading of good books; and so he had them in Spanish, that his children might read them. These books, with my mother's carefulness to make us say our prayers, and to bring us up devout to our Lady and to certain Saints, began to make me think seriously when I was, I believe, six or seven years old. It helped me, too, that I never saw my father and mother respect anything but goodness. They were very good themselves. My father was a man of great charity towards the poor, and compassion for the sick, and also for servants; so much so, that he never could be persuaded to keep slaves, for he pitied them so much: and a slave belonging to one of his brothers being once in his house, was treated by him with as much tenderness as his own children. He used to say that he could not endure the pain of seeing that she was not free. He was a man of great truthfulness; nobody ever heard him swear or speak ill of any one; his life was most pure.
My mother also was a woman of great goodness, and her life was spent in great infirmities. She was singularly pure in all her ways. Though possessing great beauty, yet was it never known that she gave reason to suspect that she made any account whatever of it; for, though she was only three-and-thirty years of age when she died, her apparel was already that of a woman advanced in years. She was very calm, and had great sense. The sufferings she went through during her life were grievous, her death most Christian.
Some Spanish news footage of her declaration as Doctor of the Church in 1970:
And some music for the occasion, by folk country legend Nanci Griffith:
Nanci Griffith, "Saint Teresa of Avila".