One consequence could be the change in Harry's relationships. His friends might initially be shocked and have to adjust to this new version of Harry. For example, Ron might struggle with his feelings towards Harry now that he's a girl.
Psychologically, Harry himself would have to deal with a new self - image. He would need to come to terms with this new physical form and how it affects his sense of self. It could also impact his connection to his Gryffindor identity and his role as 'The Boy Who Lived', now potentially becoming 'The Girl Who Lived' with all the implications that come with that.
After Harry kills Voldemort in the graveyard in the fanfiction, the magical balance might shift. With Voldemort gone, some of the dark magic that was prevalent might start to fade away. The Hogwarts School of Witchcraft and Wizardry could see a new golden age. New spells and magical theories might be explored as the fear of Voldemort no longer holds back the wizarding scholars. Harry himself might start to travel around the world to spread the news of Voldemort's defeat and also to learn more about different types of magic. His friends would also have new opportunities, like Hermione might be able to further her studies without the constant threat of Voldemort and Ron could finally relax and enjoy a more peaceful life at the Burrow.
First, Bella would have to deal with a whole new set of instincts. Her relationships with the other characters would change drastically. For example, her bond with Edward would be severely tested. Also, she'd have to adapt to the pack dynamics. She might struggle with the idea of hunting and being part of a group that has different values than her human self.
One consequence could be that the wizarding world falls back into chaos and fear. Voldemort would likely start his reign of terror again, targeting those who opposed him before. He might also try to seek revenge on Harry for initially defeating him.
One consequence could be that Harry is ostracized by some in the wizarding community who fear or misunderstand shifters. This would isolate him and make his life more difficult.
The wizarding world might be in shock. People who have always seen Voldemort as the ultimate evil would be confused. They would have to re - evaluate their views on Voldemort. Harry, on the other hand, would be in a very strange situation. He might be distrusted by some of his friends who think he has made a deal with Voldemort.
The wizarding world would likely be in a state of shock and then celebration. People would start to see Azkaban in a new light, perhaps no longer as just a place of horror but also as the site where the great evil was finally vanquished.
One idea could be that as a girl, Voldemort has to deal with the sudden change in how people perceive her. Wizards who were once afraid of the male Voldemort now underestimate her, which she uses to her advantage to secretly gather power again. Another plot could involve her exploring new emotions that come with the female form, like a different kind of vulnerability, which she initially hates but then learns to use in a manipulative way.
Hermione would probably be very curious and immediately start researching ways to reverse the transformation or at least understand it better. She'd be quite protective of Harry too.
As a girl in fanfiction, Voldemort would face challenges like having to adapt to a different body. Her magic might be affected by the transformation too. She'd also have to deal with the fact that her Death Eaters may have different reactions to her new form. Some might be less obedient or more overprotective. Plus, she would need to re - establish her reputation as a feared figure in a world that now sees her as a female, which could be quite difficult considering the gender biases in the wizarding community.
Harry could put himself in great physical danger. Voldemort might not be willing to help without exacting a high price, like Harry's own life or his magic. And even if Voldemort does seem to offer help, it could be a trap to harm Harry.