Rosa var Attre was a twin sister of Edna var Attre and daughter of Henry var Attre, Nilfgaardian Ambassador in Novigrad, who lived in the second half of 13th century. Because of her father's position and title, she lived a considerable part of her life in Var Attre Villa in Gildorf district of Novigrad. She was an avid fencer and possessed a fair amount of skill as she took lessons from soldiers and professional swordsmen.
In 1272, her father hired Dandelion as a rhetoric tutor for the twin sisters, though he wasn't successful and only managed to drive a wedge between them. Later, when Dandelion disappeared without a trace, witcher Geralt of Rivia came to ask sisters if they knew anything about that could help him with the bard. They told him behaved strangely and sang about Priscilla.
If Geralt agrees to give her lessons: The fencing lesson Geralt had given her while searching for Dandelion had thrilled her to the core and left her asking the witcher if they could meet again for a repeat. Geralt had experience teaching young women how to swing swords and agreed.
Once they were done with their lesson Geralt was supposed to escort her home. Rosa, however, was in the mood for recreation and gave him the slip during a moment of inattention. The witcher knew he needed to find her end up in trouble.
Rosa found out for herself that not all Novigraders respect diplomatic immunity. The witcher saved her from a tight spot but also discovered a dark side to her character. It was clear to them both that there would be no third fencing lesson.