Another plot twist could be that there is an external force trying to keep them apart. Maybe an enemy who knows about Sasuke's feelings and wants to use it against them, creating a lot of conflict in the story.
A possible plot twist could be that Naruto is oblivious to Sasuke's feelings at first. He might just think of her as a good friend and Sasuke has to work hard to make him see her in a different light.
It could be that Fem Sasuke is under some sort of mind - control when she kidnaps Naruto. A powerful enemy, like Orochimaru or a new villain, might have used a jutsu to make her do this. As the story progresses, Naruto would then have to find a way to break the mind - control on Fem Sasuke while also dealing with the situation of being kidnapped.
One common plot twist could be that Naruto initially resists the arranged marriage because she values her freedom and ninja career. She might see it as a hindrance to her goals. Another could be that Sasuke has some hidden motives for agreeing to the marriage, like protecting Naruto from a greater threat in the ninja world. And sometimes, a third party might try to break up the arranged marriage, believing it's not in the best interest of either Naruto or Sasuke.
One interesting plot twist could be that fem Naruto, instead of being the underdog like in the original story, is immediately recognized for her potential in the past due to her different appearance. Another could be that Sasuke, upon time traveling, tries to change things for the better but accidentally sets off a chain of events that makes the situation even worse. For example, he might try to stop certain tragedies from happening, but in doing so, creates new enemies or problems.
One plot idea could be that Sasuke initially tries to deny his feelings for Fem Naruto. He might act cold towards her but then small moments, like when she gets hurt protecting him, start to break down his walls. Another idea is that they are on a mission together and have to pretend to be a couple, which makes Sasuke realize his true feelings.
One popular 'Naruto x Fem Sasuke crush fanfiction' is 'The Unspoken Bond'. In it, Naruto slowly realizes his feelings for Fem Sasuke as they go on missions together. Another great one could be 'A Different Kind of Love' where Fem Sasuke starts to have a crush on Naruto first and it shows their relationship development in a really sweet way.
The author could use internal monologues. Sasuke could be constantly thinking about Naruto in her mind. She might admire his determination and his unique way of seeing things. This would show her growing crush on him as the story progresses.
One possible plot twist could be that Sasuke initially rejects the idea of having a baby. He might be worried about his own goals and how a family would interfere. However, as time passes, he realizes his love for Fem Naruto and the baby and decides to embrace his new role.
Another plot twist might be that Sasuke discovers a hidden enemy who is targeting their unborn child. This could lead to Sasuke having to go on a dangerous mission while Sakura is pregnant to protect their family. It would add a lot of tension to the story as Sakura is left at home worried about him.
A great plot twist could be that the one who turned Naruto into a vampire lord was actually a long - lost relative who had an ulterior motive. For example, they wanted Naruto to help them take over the ninja world using his popularity and new vampiric powers.
A really interesting plot twist could be that Naruto is not the only 'daughter' of Artemis in the Naruto world. There could be other characters who also have a connection to Artemis, and they initially see Naruto as a threat. This could lead to a lot of internal conflict within the group related to Artemis. Also, what if Artemis has some sort of dark secret or past event that affects Naruto's role in the story? For example, Artemis might have made a deal with an evil force in the past that now comes back to haunt Naruto. And perhaps Naruto discovers that her connection to Artemis is not as straightforward as she thought, and there are hidden motives behind her being brought into the world as Artemis' daughter.