I'm not sure specifically who Anna Poliatova is without more context. She could be a fictional character based on a real - life prototype or a real person whose story is being told.
Well, Anna Delvey was a person who created an elaborate false identity. She made people believe she had a huge trust fund. She used this fake identity to get credit from various places. For example, she stayed in luxury hotels and ate at expensive restaurants without paying. She was able to deceive many people because she seemed so confident and wealthy. She was very good at networking and getting into exclusive events, which helped her maintain the illusion of being a rich heiress.
Anna Karenina is a work of fiction. Tolstoy created the characters and the plot from his imagination. Although it might draw inspiration from real-life situations and human emotions, it's not based on a specific true event or person.