It's important that the author chose this type of narrator because it allows us to see the story from the perspective of one of the main characters. This gives us a deeper understanding of their thoughts, feelings, and motivations, which helps us connect more with the story.
Having Jo as the narrator impacts the story by giving it a more personal and intimate feel. We get to see the world of Little Women through her eyes, which adds an extra layer of emotion and depth to the story.
If the story were told from a different character's point of view, such as Meg or Amy, it would be quite different. For example, if it were told from Meg's point of view, we might see more focus on her struggles with society's expectations and her desire for a more conventional life. Alternatively, if it were told from Amy's perspective, we might see more of her ambition and competitiveness with her sisters.
Overall, the choice of narrator has a major impact on the story and how we experience it. Each character would bring their own unique perspective to the narrative, shaping our understanding of the characters and their relationships in different ways.