Herse Potter wasn't entirely sure when it started, but it finished when there was only a week left until the start of her second year at Hogwarts School of Witchcraft and Wizardry. And what finished was the awakening of the memories of, from what she understood, a previous life. The memories of an individual known as the Attendant of the Blood, who interestingly also shared their (or rather her) name with one of the many moons of the planet Jupiter, just like Herse herself. And that individual's name was Io. Based on the memories of her previous life, Herse learned that Io (and by extension, she) had been a very kind and gentle person who didn't let the hardships of her world put her down, traits that Herse had inherited from Io in multiple ways, which were being expressed even before Io's memories got knocked loose inside Herse's head. A major difference between Herse and Io was the fact that Io hadn't been a human, but a being known as a Revenant, which was somewhat similar to a vampire in a sense.
While Io had enhanced physical strength due to being a Revenant and physically being an adult, evidenced by her capability to wield her personal weapon, the massive halberd named the Dämmerung, Herse had (despite being completely human) deceptively high levels of physical strength for her age due to a having an extremely rare condition that hadn't been particularly documented. Her body had both deceptively and abnormally dense muscle mass, which made her significantly stronger (and heavier) than the average twelve year old and those who actually were actively exercising outside the normal amount. Strength that was displayed when she ended up lifting and hurling a piece of the broken wall in the girl's bathroom at the troll with some effort while protecting her friend Hermione Granger from said troll. It didn't really do any significant damage but it did put the troll in enough of a daze to knock it out when its club was dropped on its head. That particular incident earned Herse the gratitude and respect of the girl who gave Herse feelings of deja vu for some reason, which Herse later learned came from Io's memories, once they awakened. More specifically the memories of another Revenant who had looked and acted very similarly to Hermione Granger. The Successor of the Blood. Io's charge. Hermia Claudius. The Queenslayer.
While there were a lot of similarities between Hermia and Hermione, there were also a few differences. One of the biggest differences between them being their respective ages. Hermione was the same age as Herse whereas Hermia was somewhere in her late teens to early twenties when she was turned into a Revenant, and stopped physically aging at that point. Another difference between Hermia and Hermione was something of a normally harmless quirk of the former of the two was the fact that the Revenant had a rather poor sense of direction, often ending up walking in circles for several minutes up to multiple hours as a result despite still always ending up at her intended destination… eventually (usually several minutes or hours late) whereas the latter didn't have such a problem, unless she got distracted by something (usually a book). A quirk that sadly forced the Queenslayer to inherit the Relics of the other Successors due to being unable to find enough Vestiges, the memories lost by Revenants crystallized in the process of resurrection, to sufficiently restore the memories of the Successors. Something that, at the end of both Hermia and Io's journey, resulted in their deaths, both of them reduced to ash, even if their respective deaths occurred at different points in time. The rather heartwrenching part of it was the fact that Io's last words were that Attendant and charge would finally be together once more. While Herse was quite sure that Io was simply being metaphorical, the facts that she had inherited the Attendant's memories and shared quite a resemblance with the Revenant made the young girl have suspicions that Io (and possibly Hermia) had been given a second chance in the form of a new life through Herse (and possibly Hermione). Despite being a bit uncomfortable about the idea of having a previous life, Herse decided to simply put it aside in favor of looking forward to a new year at Hogwarts.