One possible plot twist could be that the father of Maria's baby is not who she initially thought. Maybe there was some sort of mix - up at a fertility clinic or she was deceived by someone she trusted. Another twist could be that Maria discovers she has some sort of alien - related pregnancy, given the Roswell theme, which could bring in all sorts of strange powers or abilities for the unborn child. A third twist might be that Maria decides to keep the pregnancy a secret from most of the people in Roswell, but as she tries to hide it, she gets into all sorts of comical and tense situations.
It could be Michael. Since they have a complex relationship in the Roswell series, it's possible that their relationship takes a new turn and he is the father. Maybe they had a passionate night together that led to the pregnancy.
Another plot twist could be that the pregnancy progresses at an extremely abnormal rate. This could put Renesmee's life in danger and force her and her loved ones to find a way to slow it down or deal with the consequences of a very rapid development. It could also lead to some unexpected revelations about her own nature and abilities.
One possible plot twist could be that the pregnancy is part of an alien prophecy. Maybe there's some ancient alien lore that says a child born from their union will have special powers that could save or destroy the world. Another twist could be that Liz discovers she's carrying twins, but one of them has a very different genetic makeup than the other, leading to all sorts of medical and ethical dilemmas.
One possible plot twist could be that Robin discovers he has some magical heritage that affects the pregnancy in an unexpected way. Maybe his magic interacts with Regina's and causes strange things to happen during the pregnancy, like the baby having unique powers from the start.
One possible plot twist could be that Tani Rey discovers she's pregnant during a really challenging time in her life, like when she's in the middle of an important mission. This would add a whole new layer of drama as she has to balance her personal situation with her duties.
A possible plot twist is that the goddess was actually cursed before getting pregnant, and the pregnancy is part of a larger scheme to break the curse. Percy has to go on a dangerous quest to find the antidote or solution to save both the goddess and the unborn child. It could also turn out that the child is prophesied to be a great hero or a great danger, leading to different factions trying to influence the outcome.
One plot twist could be that the pregnancy is part of an experiment by the evil scientists again. They might be using it to study the growth and abilities of the half - human, half - bird hybrids. Another could be that the father of the baby is someone unexpected, like a character who was thought to be an enemy but turns out to have a different side.
One possible plot twist could be the discovery of some hidden power in their unborn child. In the world of Percy Jackson, powers are often unexpected. Maybe the baby has a unique ability related to both Annabeth's wisdom and Percy's water - controlling powers. This could lead to various adventures as they try to protect the baby from those who might want to use its power for evil.
In the fanfiction about Maria from Roswell having a belly ache, it could be a side effect of a new power she's developing. Since Roswell is full of alien - human hybrids and people with special abilities, if Maria is on the verge of getting a new power, her body might be going through some changes that are causing the belly ache. Also, she could have been poisoned by someone who doesn't like her getting too close to the alien secrets. There are many characters in Roswell with different motives, and this could be a way to keep her out of the loop for a while.
It could be that she ate something bad. Maybe she had some alien food that didn't agree with her human digestive system. In a lot of Roswell - related fanfictions, there are often strange new foods or substances that the characters come across.