Another possible plot twist is that the oc's pregnancy might be a threat to the family's harmony in a different way. For example, some of the brothers might have plans or dreams that are now put on hold because of the pregnancy, causing conflicts within the family that go beyond just jealousy or rivalry.
Perhaps the oc's pregnancy could be part of a bigger conspiracy. Maybe someone outside the family is using the situation to try and break up the family or gain something from them. This could involve false information about the pregnancy, or attempts to manipulate the brothers' reactions to it.
One idea could be an OC who is a talented artist. She could use her art to bond with the brothers in different ways. For example, she might paint portraits of them, which could lead to some sweet and funny interactions as they react to how she's depicted them.
Well, perhaps the plot twist is that Gwendolyn is pregnant, but it's not a normal pregnancy. It could be a result of some sort of magical or scientific experiment gone wrong. For example, she was part of a study to find a cure for infertility, and instead, she ended up with an unexpected pregnancy that has strange side - effects. This would change the direction of the fanfiction completely.
A possible plot twist in a Daria pregnant fanfiction is if Daria decides to give the baby up for adoption, but then changes her mind at the last minute. This would create a lot of drama and also show her growth as a character. Or perhaps the baby has some sort of special ability or condition that Daria has to figure out how to deal with, which would be a huge change from the normal Daria - centric storylines.
The brothers could develop in their relationships with each other. For instance, they might have to put aside their differences and work together to support the oc during her pregnancy. This could lead to stronger bonds between some of the brothers who previously had rivalries.
One possible plot twist could be that the father of the baby is not who everyone initially suspects. Maybe there's some mystery or misinformation about that. Another could be that Annabeth's pregnancy is part of a prophecy that no one saw coming, and it has far - reaching consequences for the whole world in the fanfiction universe. It could also be that her pregnancy is threatened by some dark force that has a vendetta against her or her unborn child.
A really interesting plot twist could be that the pregnancy isn't a normal one. It could be some sort of magical or alien - influenced pregnancy. For example, the baby might have powers from the very start of the pregnancy that start to show in strange ways, like affecting Videl's own abilities or causing strange events to happen around her.
One great 'Brothers Conflict OC Sister' fanfiction is 'The New Sister in the Asahina Household'. It has an interesting plot where the OC sister brings a fresh dynamic to the family. The author does a wonderful job of portraying her character development as she navigates her new life with the brothers.
One idea could be that the OC is a new neighbor who moves in near the family. Natsume initially seems cold to her, but as time passes, he starts to notice her kind heart and unique hobbies. They bond over shared love for books and late - night stargazing.
Maybe a plot twist could involve their family history. There could be a hidden enemy that targeted their family long ago, and now they have to face this threat together. As they dig deeper into their past, they find out secrets that change their view of themselves and their powers. It could also be that their brotherhood is a key to unlocking an ancient prophecy.
Perhaps a plot twist could be that Naruto and Madara's mother was from a powerful and secret clan. This clan has a prophecy about two brothers saving or destroying the shinobi world. Naruto and Madara are unaware of this prophecy until later in the story. As they start to discover their true potential together, they realize that they have a choice to make. This could lead to internal struggles within each of them as they decide whether to fulfill the 'saving' part of the prophecy or be swayed by Madara's past desires for power and destruction. It would add a layer of mystery and moral dilemma to the fanfiction.