Annie is purely fictional. It was developed by the imagination of the creators rather than being rooted in real events or people. The story was crafted to entertain and engage the audience through a made-up narrative.
She could also be a symbol of a larger group. Perhaps Annie represents all the women or a specific ethnic group who have faced systemic discrimination. The 'justice for Annie' campaign, based on her true story, could be a way to highlight the broader issues of inequality and fight for justice not just for her as an individual, but for the whole group she stands for.
Indeed, 'A Place for Annie' has roots in true occurrences. The plot and characters may have been fictionalized to some extent for dramatic effect, but the core idea originated from real-life situations.