In The Vampire Diaries franchise's first tribrid, but her ability to create more tribrids is uncertain. It's natural for even unnatural species in The Vampire Diaries universe to reproduce, a supernatural evolutionary fact for the series. This was a predicament Klaus Mikaelson, Hope's father and first supernatural hybrid, struggled with in his quest to create more vampire-werewolf hybrids.
However, Hope is the only vampire-werewolf-witch tribrid that Nature has ever allowed to exist. Still, it is theoretically possible for Hope to create more tribrids on one of two conditions. The first condition is finding the loophole that would allow a hybrid witch to practice magic. A Siphoner witch-werewolf hybrid who has already activated their werewolf curse would be the likeliest candidate to become a tribrid. However, the second condition is dependent on whether Nature, along with the Ancestors, would permit Hope to create more tribrids even if it were theoretically possible and any loopholes were discovered.
Making More Tribrids Would Be A Good Idea
Increasing the number of types of vampires in the Vampire Diaries universe by allowing the creation of tribrids would either mean that there is something threatening the vampire, werewolf, and witch species that cannot be dealt with any other way. Should a threat even more perilous than Malivore threaten the natural balance, Nature could permit Hope to create tribrids to defend themselves against the new threat and impending extinction. Thus, Hope creating more tribrids would be a good idea to expand the lore of the core supernatural species while continuing to restructure the balance of power in the supernatural food chain. A similar storyline was done when the Ancestors permitted the creation of the enhanced original vampire to put the Original Vampires in check and restore balance, and Hope's own creation, so the next logical step is for Nature to allow more tribrids to exist.
Why Nature Would Probably Never Allow This To Happen In The TVD Universe
Aside from introducing interesting tribrid species, like shapeshifting witches, in The Vampire Diaries' universe to expand the lore for the sake of expansion, Hope creating more tribrids would likely not serve any purpose without introducing yet another powerful supernatural being to battle against. They wouldn't serve a purpose, that is, unless the creation of tribrids were to serve as additional keepers of the balance. More powerful than vampires and werewolves alone, they could stand alongside the witches to prevent the witches from further being ploys, hostages, and sacrifices in the vampire-werewolf war.
Legacies continued the initiative to expand the world of The Vampire Diaries with more supernatural creatures. Continuing to do the same for its core supernatural species, vampires, werewolves, and witches, would be welcomed but probably not necessary. Just as her father struggled with being the only hybrid, Hope creating more tribrids is a risk that the franchise should explore in a spinoff if only to further dramatize the loneliness of Hope being the only tribrid.