Hard to say. There might be elements of truth in it, or it could be a complete work of imagination. You'd need to look into the background and the creator's intentions to know for sure.
Since I don't know the details of this 'Lillian Hall true story', it could potentially be a story related to family heritage. Maybe Lillian Hall had a remarkable family story that has been passed down, like a story of immigration and how her family overcame difficulties in a new land. It could also be a story about her contributions to a community, such as starting a local school or helping the poor in her area.
The Great Lillian Hall is purely fictional. It was crafted by the author's imagination and doesn't draw from any true incidents or actual individuals. The story is designed to entertain and engage the readers through creative storytelling.
I'm not sure specifically which 'Lillian Hall' you are referring to. There could be many people named Lillian Hall. It would be helpful if you could provide more context, like what era she was from or what she was known for.
Another aspect could be her personal relationships. If she was a family - centered person, her story might revolve around her family values, how she raised her children, or how she maintained relationships with her relatives. Or, if she was a businesswoman, it could be about her journey in building a business, from the initial idea to facing competition and achieving success.
I'm not entirely sure specifically what 'lillian121 fanfiction' is about without more context. It could be fanfiction related to a character named Lillian, perhaps from a particular book, movie, or TV show.
Since I'm not familiar with 'lillian121 fanfiction', you might want to join relevant fan communities. There, you can ask fellow fans if they know of any good 'lillian121 fanfiction'. They may be able to point you in the right direction based on their own reading experiences.