Perhaps in the fanfiction, Female Shepard discovers that her unborn child has some sort of special power or ability. This could attract the attention of various factions in the Mass Effect universe, both good and bad. She then has to protect herself and the baby from those who would seek to use the child for their own gain.
An interesting plot could be that her pregnancy is a result of some alien experiment gone wrong, and she has to find a way to reverse it while also dealing with the fact that she's starting to feel a strange connection to the unborn child. This could lead her on a journey to find a cure and also discover the true intentions behind the experiment.
One idea could be a story exploring how Shepard and Garrus deal with the unexpected pregnancy in the midst of their galactic adventures. They might have to face challenges from their respective species' views on inter - species relationships and pregnancy.
One possible plot could be that Shepard and Tali decide to face the challenges of pregnancy together. They might have to deal with the reactions of their friends and comrades. For example, Garrus could be initially shocked but then offer his support. Tali would have to adapt to the physical changes while still being an important part of the team. Shepard, on the other hand, would be protective and ensure Tali's safety during missions. Maybe they would also start thinking about a more stable future, like finding a place to settle down away from the constant chaos of war.
One idea could be exploring how Ashley's pregnancy affects her role in the military within the Mass Effect universe. Maybe she has to take on different missions or deal with the reactions of her superiors. Another could be focusing on her relationship with the protagonist during this time. Does it become stronger or face new challenges?
Well, it could lead to a really interesting exploration of the relationship between humans and turians. Their different anatomies and cultures would present a lot of challenges during the pregnancy.
In this fanfiction, the story could revolve around the identity of the father. Is it someone from her team? Or perhaps a character she met during her travels? This could create a lot of drama and tension within the story. Also, her pregnancy might be a symbol of hope in a universe filled with so much chaos and conflict.
In some fanfictions, Shepard's pregnancy could be a result of some sort of alien experiment gone wrong. This would lead to a whole new set of challenges as she tries to figure out not only how to carry the pregnancy to term but also what the implications of this strange pregnancy are for the galaxy. Or perhaps Shepard is pregnant with a child that has some sort of special powers or abilities due to her own unique genetic makeup and all the tech and biotics she's been exposed to. This could create a story where she has to protect the unborn child from those who would seek to use it for their own gain.
A great fanfiction might be where Female Shepard has to make a difficult moral choice that goes against the Alliance's orders but is necessary for the greater good. This could lead to her being on the run while still trying to fight the Reapers. It could also involve her forming new alliances with unexpected characters in the Mass Effect universe.
Shepard's pregnancy can make her more vulnerable, which is a huge change from her usual tough, in - control self. This new vulnerability can lead to her relying more on her friends and allies, thus strengthening those relationships. For example, she might have to ask for more help during missions.
One plot idea could be Shepard and Liara dealing with the challenges of impending parenthood while also facing the threats in the Mass Effect universe. For example, they might have to protect their unborn child from the Reapers or other dangerous forces.
One idea could be exploring how Miranda's pregnancy affects her role in the fight against the Reapers. Maybe she has to step back from combat situations to protect her unborn child, causing tension within her team.