In this fanfiction, Clary is likely a newly introduced and attractive female character. However, without more context from the specific fanfiction, it's hard to say more about her personality or role in the story.
In fanfiction, the Clary and Magnus kiss is often a very passionate and significant moment. It can represent a deepening of their relationship, whether it's a newfound connection or a strengthening of an existing bond. Writers might use this kiss to show the characters' growth, as Clary might be becoming more open to the magical world that Magnus represents, and Magnus might be letting his guard down more around Clary.
They are popular in fanfiction because they both have such strong and distinct personalities. Alec is the stoic and responsible leader, while Clary is the brave and creative new addition to the Shadowhunter world. Their interactions can be full of tension, drama, and also the potential for great friendship or more, which is very appealing to write about.
Alec might also come to her rescue. As a skilled Shadowhunter, he has a strong sense of duty. Plus, he's part of Clary's group, and he wouldn't stand by and let a fellow Shadowhunter be attacked by a demon.
Jace would likely be an important character. Given his relationship with Clary, he would probably be deeply affected by the news of the baby. His reaction could range from shock to protectiveness.
Their relationship would become more centered around the baby. They would have to make decisions together for the sake of their child, which would strengthen their bond.
The relationship would evolve significantly. Before the baby, they were mainly focused on their own adventures and relationship. But now, they are parents. They would need to support each other in different ways. For instance, Jace might be more protective of Clary and the baby. Clary would be more nurturing, and they would both have to learn to balance their duties as Shadowhunters with their new family life.
Alec and Isabelle could be important characters too. As part of the shadowhunter group, they have the skills and resources to track down Jonathan. They could be the ones who gather intelligence on Jonathan's whereabouts and plan the rescue strategy, while also dealing with their own personal issues and relationships within the group.
On the other hand, there could be a glimmer of hope in their relationship. Maybe through the shared experience of the pregnancy, they start to see the good in each other. Clary might see a side of Sebastian that she never knew existed, and Sebastian might start to have real feelings for Clary and the baby, leading to a more complex and evolving relationship.
It depends on the fan base. Some fans are interested in more mature and complex storylines that might fall under Rated R, such as those involving intense emotional turmoil or more graphic action scenes. However, others may prefer more family - friendly or PG - 13 level fanfiction.