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.
Chuck is a very likely candidate as he has a long - standing and complicated relationship with Blair in the Gossip Girl series. In many fanfictions, their relationship often leads to such a situation, and the drama of them dealing with a pregnancy together is a popular plot.
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.
Another possibility could be an old flame from Lorelai's past. Maybe someone she dated briefly before coming back to Stars Hollow. This would bring in a lot of drama and unresolved feelings. Lorelai would have to deal with the fact that this person is now back in her life in a very big way, and they would have to figure out how to co - parent.
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.
Often, the Boltons are main antagonists. Ramsay Bolton in particular is a cruel and sadistic character who has caused great harm to both Theon and Sansa. His actions are a major source of conflict in many fanfictions.
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.
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.