As most sorceresses, she is sterile. She secretly sought a way of restoring her fertility. She gave her motherly love to Ciri — the child destined for Geralt by the Law of Surprise. She also taught Ciri about magic while in Ellander, at the Temple under the watchful eye of Nenneke.
Yennefer first appeared in the short story "The Last Wish" (found in The Last Wish short story collection). She later appeared in other short stories, including "Granica możliwości", "Okruch lodu" and "Coś więcej", one "non-canon" short story: "Coś się kończy, coś się zaczyna", and of course all the novels in the Witcher saga.
It is implied in the story "The Last Wish" that her attractive looks were a product of magic and had been acquired during her training, as with most other sorceresses. Geralt notes how her shoulders are slightly lopsided and by the end of the story realizes that Yennefer used to be a hunchback. Nevertheless, his love for her does not diminish.
While she never appears, nor is directly mentioned, the creators of the game did "sneak in" numerous references to Yennefer.
- In the Inn in the Outskirts of Vizima, Geralt can talk to a bard, who tells him about Dandelion, and about the ballads of the White Wolf Dandelion's sung. Among them the tale of how "Geralt married a sorceress and they live somewhere on the happy isles".
- At the very beginning of Chapter III, Triss tells Geralt that "the last time (she) felt this way, (Geralt) and a sorceress were playing with a genie".
- In Chapter IV, the innkeeper of the Country Inn at Murky Waters can tell a tale about Ciri. Near the end of it, he says that the sorceress the witcher loved tried to revive him, but died in the process.
- If Geralt chose Triss as Alvin's guardian in Chapter III, and if he answers king Foltest when questioned about their relationship that he really loves Triss, the update on the Identity-quest says, among other things: "My amnesia prevents me from remembering our relations in the past, but I have the impression I once loved a sorceress, deeply..."
- At the beginning of Chapter V, if Geralt speaks to Antoinette in the King's Hall, she mentions that she recognizes Geralt because in her home town many years ago, she saw him dancing all night with a sorceress that he was very fond of. Geralt doubts this due to his inability to dance. Antoinette questions if all Witcher's have white hair; Geralt says he is the only one, and she says she must be confused because she remembers him dancing with a sorceress.
- In Witcher DLC "Side Effects" made by CD Projekt Red as part of The Witcher: Enhanced Edition, Dandelion asks Geralt during their second conversation in jail :" ...and what about you and Yennefer?" And Geralt says to him: " I don't want to talk about this."
Yennefer appears in flashbacks in The Witcher 2.
In the end of the game it is revealed, that Yennefer is probably alive, but has amnesia like Geralt, and that she is located in the city of Nilfgaard.
Geralt will find her in The Witcher 3. It will be possible to resume a relationship with her, though Triss Merigold is still in the picture.