Well, it's difficult to say. Just from the title, it doesn't seem like a very common or well - known vampire fanfic. There could be a small niche of readers who like it, but without looking into fanfic databases or forums dedicated to vampire stories, we can't really know for sure. It might also depend on how well - written it is, the uniqueness of the plot, and how it engages the readers who are into this type of genre.
I'm not sure where you can specifically find that fanfic. You could try searching on some well - known fanfic platforms like Archive of Our Own or Fanfiction.net.
One interesting plot idea could be that the OC is a new student in town. Benny notices her right away and there's an instant connection. However, the OC has a secret power that she's trying to hide from everyone, including Benny. As they grow closer, she has to decide whether to trust Benny with her secret. Another idea is that the OC is actually from a family of vampire hunters, but she falls for Benny, a vampire. This creates a huge conflict within her as she has to choose between her family's legacy and her feelings for Benny.
To write a good OC, start with giving her a unique personality. For example, she could be really shy but have a fierce determination inside. Give her some hobbies or interests like reading ancient vampire lore books. This not only makes her more interesting but also gives a reason for her to interact with Benny. Also, give her a backstory. Maybe she lost her parents at a young age and was raised by an eccentric aunt who taught her all kinds of strange things.
Their relationship could develop uniquely if they had to swap powers for a while. Ethan would experience what it's like to be a vampire like Erica, and she would get a taste of being human. This would give them a new perspective on each other. For example, Erica might realize how difficult it is for Ethan to be around vampires all the time, and Ethan would understand Erica's vampire instincts better.
One plot idea could be that Ethan and Erica have to team up to fight a new, powerful vampire that has come to town. They start off bickering as usual but as they face more and more danger, they realize their feelings for each other are deeper than they thought. Another could be a time - travel plot where they are sent back in time to the era when vampires first emerged and have to find a way back while also dealing with their relationship in a completely different setting. Or perhaps a plot where Erica gets cursed and Ethan has to find a way to break the curse, during which they grow closer.
A common story could be when the wife is initially hesitant about hiring a babysitter. But as time passes, she realizes that the babysitter is very reliable and trustworthy. This gives her more freedom to pursue her own hobbies or work outside the home.