[2] Modern Polish historians usually named her Eufrozyna, but in sources she was mentioned mostly as Eufrazja.
They were Siemowit II, Trojden I and wife of Władysław Prince of Leginca (her name is unknown).
This theory was based on fact that she must be at least 14 years old, when she get married in 1306 (her son Jan I was born in 1307).
[6] The exact date of Euphrosyne's marriage to Władysław of Oświęcim is unknown.
Euphrosyne's cousin Wenceslaus III of Bohemia was married to Władysław's sister Viola Elisabeth of Cieszyn.