Yuri traveled through time.
She originally thought that she would be like the heroine in the fan fiction, or be the mastermind behind the scenes and take charge of the overall situation, or be the heartthrob and have a sweet love with the protagonists. In the end, she decided to lie down and be a salty fish, silently watching the protagonist group fight against Voldemort.
However, things did not go as she expected. In this world, she felt the power of family and friendship. For the one she loved, she put aside everything and fought against Voldemort. Before she knew it, she had integrated into this world.
Concept: A time-traveling girl feels love in the HP world