One possible storyline could be them dealing with the initial shock and then preparing for the new arrival. They might face challenges from their superhero duties while also getting ready to be parents. For example, they could be worried about how to keep their child safe in a world full of villains.
There are various storylines where they team up to face villains and save the day. One notable one is when they work together to stop a powerful meta-human threat.
They would likely become more protective of each other. With a baby on the way, Kid Flash might be more cautious about putting Artemis in dangerous situations during their superhero work. And Artemis would also be more aware of Kid Flash's safety as she's carrying their child.
One great storyline could be them going on a secret mission together. Maybe they have to infiltrate an enemy base where their speed and archery skills are both crucial. Another could be a story where they get stranded in an alternate dimension and have to rely on each other to get back home. It could explore their friendship and how they grow to trust each other more deeply.
One popular storyline is them going on a mission together without the rest of the team and facing a powerful new villain. This allows for a lot of character development between them as they rely on each other's skills. Another is a story where they have to protect a civilian who has some sort of special power. This puts them in a situation where they have to work closely and also deal with their own feelings towards each other.
One possible storyline could be that Artemis tries to hide her pregnancy while still fulfilling her duties. She might face challenges like dealing with her own changing body and the risk of being discovered. Another could be that she searches for the father in secret, all while feeling alone and scared.
Teamwork is also a big theme. Since they are both part of the Young Justice team, many fanfictions focus on how their skills complement each other during missions. For example, Kid Flash's speed and Artemis's archery skills can be combined in unique ways to defeat villains. There are also themes related to family and identity, as both characters have their own family issues and aspects of their identity that are explored in fanfiction.
In such a fanfiction, the author might focus on the cultural differences between their two characters. Kid Flash is known for his speed and somewhat carefree attitude, while Artemis is more serious and skilled in archery. Their marriage could be a story of two different worlds coming together, and how they learn from each other to make their relationship work.
One possible scenario could be during a moment of victory. After a tough battle, as they catch their breath, the adrenaline and shared sense of accomplishment lead to an unexpected moment of closeness. Their eyes meet, and before they know it, they share their first kiss. It's a spontaneous act, born out of the bond that has been growing between them through all their adventures.
A common theme is the exploration of their hidden feelings. In the original series, their relationship might be somewhat ambiguous, so fanfiction often dives into how they really feel about each other beneath the surface. Another theme could be the consequences of their relationship becoming public within the team. It adds drama and conflict to the story.
The plot could revolve around an alternate universe. In this universe, they are not superheroes in the same way. Artemis is more of an artist and Kid Flash is just a regular guy with a love for speed. They meet in a more normal setting, like a coffee shop. As they get to know each other over time, their relationship develops and the kiss is a natural progression of their growing feelings.