She accompanied Shirley on his diplomatic missions to England and other royal houses in Europe for king Abbas. On their first trip together, Teresia and Shirley visited the Grand Duke of Muscovy, Pope Paul V in Rome and the King of Poland. There, Teresia remained in a convent in Kraków for some time, while her husband went on to visit Prague, where Emperor Rudolph II (r. 1576–1612) bestowed him with the titl of Count Palatine. Rejoined, they arrived in Rome around November 1608 and met Ali Qoli Beg (the king's ambassador, with whom they had an audience with the pope) before leaving for Savoy, France, Flanders and Spain, where they remained for fourteen months.
Teresia and Shirley then left for Holland and England. Their only child, a son named Henry, was born in the autumn of 1611 at the Shirley home in Sussex. His godparents were the Prince of Wales, for whom he was named, and Queen Anne. On their way back to Safavid Iran in 1613, they decided to turn young Henry over either to the care of the queen, or Robert's own family in Sussex. On Teresia's last mission with her husband they visited Rome in 1622, where Anthony van Dyck (then 23-year old) painted their portraits. They then went to Poland, and visited England in 1623 for the last time. Returning to Qazvin (at that time the capital) from the last mission with Shirley, he and Teresia were rewarded by the king with valuable gifts. Shirley and the envoy, however, became seriously ill with fever shortly after their arrival and he died shortly after. Some nobles in Iran were very envious of the king's treatment of Teresia and her husband and after his death, they started plundering her wealth and accused her of converting to Christianity from Islam, and not actually being born a Christian. In those days these were fatal accusations, but Teresia convinced her judges that she was, is and always will be a devout Christian.
After three years in Safavid Iran since returning from her last trip with her husband, Teresia was granted permission to leave her country of birth forever. She lived in Constantinople for three years, receiving a certificate from the commissary general of the Dominicans in the East on 21 June 1634 attesting to her pious conduct. Around that time, she decided to retire to a convent in Rome which was attached to the Carmelite Santa Maria della Scala church. On 27 December 1634 she arrived in Rome and was received kindly by Pope Urban VIII, who entrusted her to the Carmelites. Teresia bought a house next to the church; in 1658 she had Robert's remains transported from Isfahan to Rome, where he was reburied in the convent. In the Carmelite convent, she devoted herself to charity and religion until her death at age 79 in 1688. Teresia was buried at the convent, where she had lived for forty years. She had her headstone inscribed, "Teresia Sampsonia Amazonites Samphuffi Circassiae Principes Filia" (translated by David W. Davies as "Teresia Sampsonia, native of the region of the Amazons, daughter of Samphuffus, prince of Circassia").
During her five journeys between Persia and Europe, she was noted by contemporary writers, artists and European royal houses. According to travel writer Thomas Herbert, Robert Shirley "was the greatest Traveller of his time"; Herbert also admired the "undaunted Lady Teresia", whose "faith was ever Christian, her parents so noble and her country of origin Circassia".
