Ruth Finley could be a character in a story. Maybe she's a protagonist who has to overcome various challenges. It could be a story about her personal growth, relationships, or her achievements in a certain area like career or family. Without reading the story, it's hard to say exactly who she is.
Since we lack details, Ruth Finley could be anyone. She might be an artist who has created amazing works but is only known in a specific art circle. Or she could be a scientist who made some contributions in a particular research area but isn't widely known outside of that scientific community. There are just so many possibilities.
Often, there are themes related to her skills and how she uses them in different situations. For instance, her computer hacking skills or her combat training. There can also be themes of her facing challenges and overcoming them, whether it's dealing with a new villain in the Young Justice universe or personal issues within the team. Sometimes, her family background and how it influences her actions in the story are also common themes in these fanfictions.
The Book of Ruth is typically regarded as fiction. It presents a narrative that might incorporate fictional elements to convey moral or religious messages.
You can try fanfiction.net. It has a large collection of Young Justice fanfictions, and there are likely many focused on Barbara Gordon. Another option is Archive of Our Own (AO3). It's known for its wide variety of fan-created works and has a great tagging system to help you find specific Barbara Gordon - related Young Justice fanfictions.