What is "brnjaca"

Brnjača (, 1253– 1264) was a Serbian princess, the daughter of King Stefan Uroš I (r. 1243–76) and Queen Helen of Anjou. Her brothers were Stefan Dragutin and Stefan Milutin. The oldest depiction of her, when she was ca. 12 years old is in the 1264 fresco of the burial of Queen Ana Dandolo (d. 1258) at Sopoćani, shown with a crown, although her appearance is anachronistic. She is depicted on a fresco in the narthex of Visoki Dečani dating to ca. 1345, alongside Simeon Uroš and Teodora-Evdokija. She is depicted in the Nemanjić family tree fresco of Visoki Dečani. She was a nun, and did not marry. It was earlier believed that Brnjača was the nickname of her mother (named so due to the main estate of her feudal state, Brnjak).