Marriage to Sandalj Hranić
When Ladislaus of Naples sold his rights to the Kingdom of Dalmatia to the Republic of Venice and retreated from the Balkans in 1409, many local nobles allied themselves with the Holy Roman Emperor Sigismund and accepted Ostoja as the King of Bosnia. This seriously weakened the position of Hrvoje Vukčić Hrvatinić, a Grand Duke of Bosnia, whose niece Katarina was a second wife of Sandalj Hranić, a Grand Duke of Hum. In such circumstances Sandalj decided to ally with emperor Sigismund in mid 1411 and to establish closer connections with Sigismund's important ally Stefan Lazarević. In December 1411 Sandalj divorced his wife Katarina and married Stefan's sister Jelena at the end of the same year. Jelena married Sandalj because she wanted to strengthen the position of her son. With this marriage, Sandalj, the most dangerous enemy of Balša III, became his stepfather and protector. Although it spoiled Sandalj's relations with Hrvoje, it also strengthened traditionally close relations with the Lazarević family. Although Jelena was in her forties, Sandalj hoped they would have children and in 1413 deposited some money at a transactional account with the city of Dubrovnik for the child they would eventually have.
Jelena went to live with her husband at his court in Blagaj in Herzegovina while Balša remained as the only governor of Zeta. In his second marriage, concluded in 1412 or at the beginning of 1413, Balša III married Bolja, a daughter of Koja Zaharia who was a Lord of Sati and Dagnum in Albania. In 1413 Balša issued a charter to the church dedicated to Saint Nicholas he built in Praskvica Monastery together with his mother Jelena.
Sandalj had a court in Novi (modern day Herceg Novi) where he spent some time every year, usually in winter and spring. Beginning in 1424, Jelena spent a good part of the year at this court, accompanied by her sister Olivera.
At the beginning of February 1426 a special ceremony was dedicated to Jelena and Sandalj in Dubrovnik when they attended the feast of Sveti Vlaho (Saint Blaise), the city's patron saint. Jelena intended to be buried in the church she would build in Dubrovnik. Initially, Dubrovnik was interested in accepting her wish on the condition that she help them take control of Novi, its rival in salt-trading. That is why Dubrovnik proposed to Sandalj to build an Orthodox church and home for old and sick people in 1434. Sandalj died in 1435 before he replied to their proposal. He was succeeded by his nephew Stjepan Vukčić Kosača who was a son of Sandalj's brother Vukac. After Sandalj's death Jelena did not interfere in the governing of the realm previously controlled by her husband but went to live at the seaside, probably in Novi. In September 1435 Jelena asked the Ragusans to allow her to build a church in Dubrovnik in which would be her grave. Since circumstances had changed after Sandalj's death, the Ragusans rejected Jelena's request although it was supported by her nephew, Serbian Despot Đurađ Branković. They justified their refusal with the lack of the approval of the Pope.