Teresa Ysseldijk was born on November 13, 1897, in Apeldoorn, the Netherlands, the daughter of a Catholic family full of faith. After a stay of 6 years in Ochtrup, Germany, where her father died, she lived with her family in Enschede until she entered the convent.

Teresa suffered a lot during her childhood and began very early in life to love her suffering. From her pious mother she learned to love the Mother of God and the Sacred Heart of Jesus. When her health improved, she asked to enter the Carmel of the Divine Heart of Jesus. She entered the convent in Tilburg on October 2, 1917, takin the name of Sr Mary Teresa of the Most Holy Trinity. She professed her vows on July 2, 1919. Driven by a great zeal for the missions, she travelled to the USA with seven other sisters in December 1919.

Shortly after her arrival in the new world, she was stricken with an illness, a serious kidney disease, discovered too late by doctors. She endured this further suffering for five years in the convent of St. Charles, Missouri, with indescribable patience and a smile on her lips. She wanted to serve God in the Order, working in silent union with Him.

When work was no longer possible, she bore her pain in silence, hidden from the world.

She died a holy death on March 10, 1926, in St. Mary's Hospital in St. Louis.

On November 12, 2015, the decree of validity was granted to the Inquiry on her «life, virtue and reputation of holiness».