She was the daughter of despot Sratsimir and Keratsa Petritsa of the Shishman family, a descendant of Tsar Ivan Asen II. She was the sister of tsar (emperor) Ivan Alexander of Bulgaria, Ivan-Alexander, John Komnenos, Michael and Theodora.
Stefan Dušan was crowned King of Serbia at Svrčin on 8 September 1331 (Nativity of the Theotokos). A year later, most likely 26 April 1332 (Thomas Sunday), Dušan married Helena. Previously, it was erroneously assumed that the marriage took place on Easter (19 April), however, marriages are not instituted on Easter in the Orthodox Church. Their wedding night was held at the royal court in Skopje.[3] The marriage was arranged as part of the peace agreement between Bulgaria and Serbia.
This marriage provided one son, Stefan Uroš V, a daughter, Theodora, who became a consort of Ottoman Sultan Orhan when she was twelve and Orhan seventy, and possibly one other daughter, named Irina or Irene. According to John V. A. Fine, she is the same "Irene" who was wife of Gregorios Preljub, the Serbian governor of Thessaly who died in late 1355 or early 1356. They were parents to Thomas II Preljubović, Ruler of Epirus from 1367 to 1384. Irene married secondly to Radoslav Hlapen, lord of Kastoria and Edessa.
Helena lived in the Republic of Venice in 1350. On her husband's death in 1355, Helena inherited part of Bulgarian lands between the lower Vardar and the Mesta. She also received the Chalcidic peninsula, basing her court at Serres. She was a regent of Serbia between 1355 and 1356 for her son.
In 1359, Helena became a nun under the monastic name Jelisaveta (Serbian: Јелисавета). However, she continued to play an active role in politics, governing the region of Serres until 1365. After that, she retired from political life, overseeing reconstruction and renovation of several monastic communities, until her death in 1374. Queen Helena died on November 7, 1374, the date of her death is given in a Hilendar manuscript.