As others have more or less said, this seems for the moment to be taking relatively seriously it's premise of having a bunch of jealous and obsessed nobility lying around. It's like they're living in a world where everyone is just a little bit more prone to giving in to unhealthy obsession.
The protagonist isn't given magical mary-sue powers to resolve it all, not beyond a bit of foresight and common sense beyond her age inherent in the plot. It's resulting in what's turning out to be surprisingly decent light thriller elements and what could even yet turn itself into a solid plot if it wanted to (though that last bit might be too much to ask of an isekai).
But it has soft moments too, so far, to keep it from being an angst-fest. Overall, the sum of these parts actually forms something quite palatable... I kind of like it.