Another possibility is that the father could be a new character introduced in the fanfiction. This new character could be a powerful lord from a far - off land who comes to Winterfell, falls in love with Sansa, and they have a relationship. Or perhaps it's a mysterious figure with magical powers who impregnates Sansa as part of a grander scheme in the magical and political landscape of Westeros.
If Sansa was pregnant in this fanfiction, it could potentially be a catalyst for a new alliance. Jaime, despite his past actions, has certain skills and influence. This could be used to protect Sansa and the unborn child. However, they would face many enemies. The Lannisters might not accept Sansa easily, and the Northmen may be skeptical of Jaime's intentions. Sansa, on the other hand, would have to use her wits to navigate through this difficult situation, perhaps trying to use the pregnancy to her advantage in the power games of Westeros.
One interesting fanfiction could be where Sansa uses her new - found wisdom and political acumen in a situation that has a 'lemon - like' twist, perhaps in a negotiation with a difficult lord where she offers something unexpected, like a rare lemon - scented perfume from the south in exchange for loyalty. However, this is just a speculation as there are countless fan - created stories out there.
Theon Greyjoy can also be an interesting character to pair with Sansa. Their complex relationship can be developed further in fanfiction. Maybe Theon is trying to make amends for his past actions towards Sansa and they end up forming an unexpected alliance to face common enemies.
A possible storyline is that Sansa's pregnancy is a result of a secret love affair. The identity of the father could be a mystery that drives the plot. As she tries to keep the pregnancy a secret at first, she has to deal with the internal struggle of whether to reveal the truth or not. Meanwhile, political intrigues in the background keep the story exciting as different factions might have different interests in her unborn child.
It could also be Littlefinger's followers or remnants of his schemes. Since Littlefinger had his own plans involving Sansa, his influence might still linger in fanfiction, and those who were loyal to him could oppose Sansa and Theon's attempts to bring stability to the North.
In some interpretations, it could be another powerful ninja who has a secret relationship with Madara. Maybe it's someone from a rival clan, which would add a lot of drama and conflict. For example, if it were a member of the Senju clan, considering the long - standing feud between the Uchiha and Senju.
Perhaps Sansa's child is fathered by a character who is not a traditional choice. This could lead to all sorts of political intrigue and family drama. For example, if the father is from a formerly enemy house, it could force a re - evaluation of alliances in Westeros. The birth itself could be a difficult and dangerous process, with Sansa having to fight off those who would try to harm her or the unborn child during her pregnancy.
Sometimes minor characters in relation to Jon and Sansa are well - written too. For instance, Davos could be written in a way that he acts as a wise advisor to both Jon and Sansa. His no - nonsense attitude and loyalty can add depth to the story. He might be the voice of reason when Jon and Sansa have different opinions on how to deal with a particular situation.
In one scenario, the father could be another werewolf from her pack. It could be a relationship that was kept secret, and the pregnancy now forces them to come forward and deal with the consequences.
Another possibility is that it's an enemy turned lover. There could have been some sort of conflict between Yuki and another character initially, but as they got to know each other better, they fell in love and now she's pregnant. This would create a complex dynamic in the story as they have to deal with their past and their new future together.