Well, a plot could revolve around Felicity having a difficult pregnancy. Oliver then has to balance his duties as the Green Arrow and being a supportive partner. They could also have a story where they are trying to prepare for the baby's arrival while dealing with a new villain in Star City. This villain could be targeting pregnant women, making Felicity a prime target. So, Oliver has to stop the villain while also taking care of Felicity.
One idea could be that Oliver and Felicity's baby has some sort of unique meta - human ability that they have to protect it from those who would use it for evil. Another could be the baby getting kidnapped and Oliver and Felicity having to team up with their old Arrow - team friends to get it back. They could also face challenges in raising the baby while still being vigilantes.
Perhaps there's a villain who targets Felicity because of her pregnancy. This villain could see the baby as a way to get back at Oliver. So, Oliver has to go to great lengths to keep Felicity hidden and safe. Meanwhile, Felicity could be using her intelligence to find a way to outwit the villain from her hiding place, all while dealing with the physical and emotional changes of pregnancy.
One good example could be a fanfiction where Felicity discovers she's pregnant and Oliver has to balance his vigilante duties with being a supportive partner. They might face challenges like protecting their unborn child from their enemies in Star City.
One idea could be them facing challenges in their married life due to Oliver's vigilante duties. Maybe Felicity gets worried every time he goes out at night. Another could be them planning to start a family and all the joys and concerns that come with it. Or perhaps they take a trip together and encounter some old enemies during their journey.
A fanfic could also explore the reactions of the other characters like Diggle and Thea. Diggle might offer his fatherly advice since he has experience with fatherhood. Thea could be excited about becoming an aunt and start planning all kinds of things for the baby. This would add a touch of family - like warmth to the often - intense Arrow universe.
One idea could be that Oliver and Felicity face the challenges of impending parenthood while also dealing with threats to Star City. Maybe Felicity's pregnancy makes her a target, and Oliver has to be extra vigilant in protecting her. They could also have sweet moments of preparing for the baby, like decorating the nursery together.
One common plot idea is exploring their life after the events of the show. For example, how they handle raising a family while still being involved in the vigilante world. Another idea could be alternate universes where they meet under different circumstances, like Felicity being a superhero herself and Oliver being a tech genius who helps her.
Their friends could be overjoyed. Diggle might offer his support and protection, as he has always been a loyal friend. Thea could be excited about becoming an aunt and start planning all kinds of baby - related things. Curtis might use his tech skills to create some amazing baby gadgets for them.
Another plot could revolve around the challenges of raising a baby in their dangerous world. They have to constantly protect the baby from their enemies. Maybe there are villains who try to kidnap the baby to get to Oliver or Felicity. So they have to set up a super - secure hideout and enlist the help of their friends like Diggle.
A possible plot is that Felicity discovers she's pregnant at a very inconvenient time, like right in the middle of a major battle plan against a big villain. This could lead to a lot of internal conflict for her and Oliver as they decide whether to continue with the plan or focus on the pregnancy. Also, they could face challenges in preparing for the baby, such as finding a safe place to live considering their dangerous enemies.