Ezra Bridger's relationship with Clan Wren also offers interesting writing opportunities. He's an outsider who gets involved with the clan. His different perspective and the way he influences and is influenced by the clan members can be explored in fanfiction.
Sabine Wren is definitely one of the most interesting. She's a complex character with a lot of skills. She's an artist as well as a warrior, and writing about her inner conflict between her loyalty to her clan and her newfound beliefs with the Rebellion can be really engaging.
Then there's Ursa Wren. As a powerful figure in the clan, she has a lot of authority. Writing about her leadership and how she makes decisions that affect the whole clan, especially in times of crisis like dealing with the Empire's encroachment, can make for a great story.