Another place to check could be Fanfiction.net. It has a large collection of 'Game of Thrones' fanfiction. When searching for female Benjen Stark fanfiction, be sure to use specific keywords in the search bar. Maybe you'll find a story where she has a special relationship with other characters from the show, like Jon Snow or Arya Stark.
It could also focus on her family relationships. Maybe she has a closer bond with Sansa or Catelyn Stark. She could be involved in the family's political struggles, like trying to protect the Stark name during the War of the Five Kings. She might use her knowledge of the North and the secrets beyond the Wall to her family's advantage.
Well, Uncle Benjen Stark was a significant figure in 'Game of Thrones'. He was part of the Night's Watch, which guards the Wall. He went missing for a long time. Turns out he was turned into something not quite alive by the magic of the Children of the Forest. His return was crucial as he was able to assist Bran, like guiding him and providing some protection when Bran was in dangerous situations north of the Wall.
Arya Stark is one of the most beloved characters from 'Game of Thrones'. She is initially presented as a bit of a tomboy, not conforming to the ladylike standards of her society. As the story progresses, she becomes a key player in the power struggles of Westeros. She is brave, resourceful and has a very distinct personality that makes her stand out among the many characters in the series.
One great fanfic could be about Arya Stark rebuilding Winterfell as the last Stark. It might explore how she uses her skills she learned during her travels to bring back the glory of her family's home. She could train new guards, establish trade routes, and make Winterfell a stronghold again.
In some fanfics, Arya Stark might be presented as the last Stark, but it really depends on the specific plot and direction the fanfic author takes. There could be plot twists where other Starks are revealed to still be alive.
Bran Stark's story is one of great transformation. He starts as a young boy full of curiosity. After his fall and becoming a cripple, he discovers his warging ability, which allows him to enter the minds of animals. Later, he trains with the Three - Eyed Raven and gains the power to see the past and future, playing a crucial role in the fight against the Night King and the overall fate of Westeros.
It could be a bastard child of a Stark that was kept hidden for some reason. Maybe for fear of political ramifications or because of some dark family secret.
Another idea for a fanfic is that Arya discovers she's not really the last Stark. There could be a long - lost relative hidden away. She then embarks on a journey to find this person. Along the way, she has to overcome many obstacles and face new enemies, all while trying to keep the hope of the Stark family alive.