I like to think that Bianca had more Demeteresque powers, in the sense that she had control over a soil's fertility, along as having bone and skeleton manipulation, although I never imagined her being able to communicate with ghosts. You know, just because Hades is also the god of the ground. One day, she might bring a tomato plant home from school (I dunno how historically accurate that would be, but because of the even clearer sexism at the time, I suspect the girls would've been taught some form of gardening) for a project to grow it over several weeks. She has an argument with Nico, so obviously gets pretty stressed, and her powers get out of control and the plant is fully grown overnight because soil and then she'd have to bring in what would essentially be a tree and everyone sort of stares at her. This keeps happening and plants just start popping up out of nowhere, so in the end someone realises it's her and it's actually one of the reasons why the di Angelos inevitably move, along side people thinking Nico's seeing visions, and- well- ghosts