One plot idea could be that the Jessie OC has a special power that is hidden from the other vampires. For example, the ability to see the future which she uses to protect the family she babysits for from impending vampire threats. Another idea is that she is from a different vampire clan and has to keep it a secret while babysitting, and there could be a conflict when members of her clan come looking for her.
Maybe the Jessie OC in the fanfiction is an amateur vampire, still learning the ropes. She could accidentally use her vampire powers in front of the kids she babysits, like super speed when chasing a runaway ball. And then she has to come up with really creative excuses to cover it up. Also, she might fall in love with a human in the neighborhood, which would create a whole new set of problems and storylines.
One idea could be an OC who is a new vampire in town and befriends the babysitter vampire. They could team up to protect the neighborhood from a new threat, like a group of werewolves.
One idea could be that the vampire babysitter has to protect the kids from an ancient vampire hunter who mistakes the babysitter for a rogue vampire. Another could be that the kids discover a secret power within themselves that helps the babysitter in her vampire - related troubles. Maybe the babysitter has to attend a vampire council meeting and the kids accidentally tag along and cause chaos.
To develop the character of Jessie, start with her backstory. Decide where she came from, how she became a vampire. Maybe she was turned against her will by an evil vampire. Then focus on her personality traits. Is she shy? Outgoing? You can also show her relationships with other characters. For example, how she interacts with the kids she babysits, whether she's strict or more like a fun big sister.
Maybe the vampire's pregnancy is the result of a unique vampire ritual. The babysitter has to figure out how to raise a half - vampire baby in a human world. She could start to teach the kids she babysits some vampire - friendly things to prepare them for the new addition.
One idea could be exploring the backstory of the vampire babysitter more in - depth. Maybe she has a hidden past in a different vampire clan that she's trying to keep secret from the family she babysits for.
One plot idea could be that the gender - swapped vampire babysitter has to deal with different social expectations in the human world while still trying to hide their true nature. For example, they might struggle with how to interact with the kids in a more 'gender - appropriate' way according to human norms while also having to keep their vampire instincts in check.
Another interesting idea is to focus on the relationship between the babysitter and the kids they are taking care of. What if one of the kids finds out about the vampire nature in a really cute or funny way? It could lead to some heartwarming and humorous moments in the fanfiction, like the kid trying to keep it a secret while also being super curious.
The addition of an original character (OC) to the existing 'My Babysitter's a Vampire' universe makes it interesting. It allows for new relationships to be explored, especially involving Benny. For example, the OC could be a new type of supernatural being that Benny has to figure out how to interact with.
Another idea is that the characters from 'My Babysitter's a Vampire' are brought to the Naruto world. They are shocked by the existence of ninjas and the different kind of powers. The babysitter, who is a vampire, could use her vampiric abilities to help Naruto in a battle against a powerful enemy, while Naruto helps her adapt to this new and strange world.
Another fanfiction concept could involve a character from 'My Babysitter's a Vampire' getting involved in the ninja world of 'Naruto'. Maybe Benny could travel to the Hidden Leaf Village. He would be really intrigued by the different jutsus and might try to learn some of them, while also introducing the idea of vampires to the ninjas. This could lead to some really interesting interactions and training sessions between the two groups of characters.