The subject of the article is the issue of the name of the eldest daughter of Duke Władysław Opolczyk, who was a nun in the Poor Clares monastery in Stara Buda. It came from the prince's first marriage with Elizabeth, the daughter of the Wallachian voivode Nicholas Alexander Bessarab. In the current historiography, there is confusion about her name. There is only one source that mentions it - a document by Władysław Opolczyk from 1369. However, its original has been lost and the publication contains many errors. Some historians suggested that Władysław Opolczyk's daughter was named Kinga. This belief was based on a document of the court judge Jakub of Szepes from 1373, where Elizabeth, Jenslin's daughter, was defined as the daughter of the Duke of Opole. However, Kinga was not Władysław Opolczyk's daughter, but his sister. Her name appears frequently in other sources from this period. Ultimately, the name of Władysław Opolczyk's eldest daughter remains unknown.