There could also be some minor characters that become more important in this fanfiction. For example, Harry's parents, James and Lily. Since Harry is changing the past, they might have more of a role to play. Or perhaps characters like Sirius Black or Remus Lupin could be involved in different ways due to the changes Harry makes in the past.
Another plot might be Harry changing his relationship with Snape. He could go back and try to understand Snape better from the start, which might lead to a very different dynamic between them. This could potentially change how Snape behaves towards Harry and the other Gryffindors, and also how Harry views Snape throughout his time at Hogwarts.
Often, the theme of self - discovery is present. By changing the past, Sakura gets to learn more about herself and her capabilities. Also, the theme of preventing a tragedy is quite common. Maybe there was a big disaster in the original timeline that she aims to avoid. In these fanfictions, the exploration of the butterfly effect is also a thing. Every change she makes in the past has consequences in the future, and this can lead to interesting plot developments.
One good small change could be in the character development. For example, Neville could start showing his courage a bit earlier in the fanfiction. This would add an interesting twist as it would make the story deviate slightly from the original in a positive way. It could also change the dynamics within the group of friends at Hogwarts.
The contents of the Spring Festival's Eastern Mountain Rebellion were: Chapter 1: Blood and Yellow Soil in the Imperial Palace, Chapter 2: Thunderstorm, Chapter 3: The World Shakes, Chapter 4: Abandoned Crown Prince, Chapter 5: The Sovereign of the East Sea, Chapter 6: The Crescent Moon Shines on Eastern Mountain, Chapter 7: Fleeing to the Furious Sea, Chapter 8: Pursuit, Chapter 9: A Stunning Spear, Chapter 10: Great Grandmaster, etc.
The contents of the Spring Festival's Eastern Mountain Rebellion were: Chapter 1: Blood and Yellow Soil in the Imperial Palace, Chapter 2: Thunderstorm, Chapter 3: The World Shakes, Chapter 4: Abandoned Crown Prince, Chapter 5: The Sovereign of the East Sea, Chapter 6: The Crescent Moon Shines on Eastern Mountain, Chapter 7: Surrender to the Furious Sea, Chapter 8: Pursuit, Chapter 9: A Stunning Spear, and Chapter 10: Great Grandmaster.
The contents of the Spring Festival's Eastern Mountain Rebellion were: Chapter 1: Blood and Yellow Soil in the Imperial Palace, Chapter 2: Thunderstorm, Chapter 3: The World Shakes, Chapter 4: Abandoned Crown Prince, Chapter 5: The Sovereign of the East Sea, Chapter 6: The Crescent Moon Shines on Eastern Mountain, Chapter 7: Fleeing to the Furious Sea, Chapter 8: Pursuit, Chapter 9: A Stunning Spear, Chapter 10: Great Grandmaster, etc.
The contents of the Spring Festival's Eastern Mountain Rebellion were: Chapter 1: Blood and Yellow Soil in the Imperial Palace, Chapter 2: Thunderstorm, Chapter 3: The World Shakes, Chapter 4: Abandoned Crown Prince, Chapter 5: The Sovereign of the East Sea, Chapter 6: The Crescent Moon Shines on Eastern Mountain, Chapter 7: Fleeing to the Furious Sea, Chapter 8: Pursuit, Chapter 9: A Stunning Spear, Chapter 10: Great Grandmaster, etc.
The contents of the Spring Festival's Eastern Mountain Incident included: Chapter 1: Blood and Yellow Soil in the Imperial Palace, Chapter 2: Thunderstorm, Chapter 3: The World Shakes, Chapter 4: Abandoned Crown Prince, Chapter 5: The Sovereign of the East Sea, Chapter 6: The Crescent Moon Shines on Eastern Mountain, Chapter 7: Going to the Furious Sea, Chapter 8: Pursuit, Chapter 9: A Stunning Spear, Chapter 10: Great Grandmaster, etc.
The contents of the Spring Festival's Eastern Mountain Incident included: Chapter 1: Blood and Yellow Soil in the Imperial Palace, Chapter 2: Thunderstorm, Chapter 3: The World Shakes, Chapter 4: Abandoned Crown Prince, Chapter 5: The Sovereign of the East Sea, Chapter 6: The Crescent Moon Shines on Eastern Mountain, Chapter 7: Going to the Furious Sea, Chapter 8: Pursuit, Chapter 9: A Stunning Spear, Chapter 10: Great Grandmaster, etc.