I can kind of appreciate that this is a twist on the "I was framed as the villainess" sub-genre of villainess/engagement-breaking stories where the conceit is that everyone seems to know that the MC isn't really bad and it's only the framer and the guy the to whom the engagement is broken that aren't totally in the know (though here he seems at least somewhat aware that it doesn't make much sense). The problem is that they don't really pay off that fact in an interesting way and it feels like there's not really anywhere to go that will make much conflict. The framer girl is a lower noble/maid so she has no political power to protect herself with. The lord/fought-over guy is not 100% totally on her side as he's been seen wavering a bit. There's no indication of hypnosis magic or anything of the sort to force things in one direction. And nothing that Lydia has done has even come close to actually being construed as bad.
All that can really happen is that Lydia makes her accusations, everyone agrees with them, and she moves on to the guy that was just introduced to find real love and companionship. I don't want big huge drama and contrived twists where she loses at every turn in spite of having the high ground and being the protagonist. But there's just no meat to this one.
I just don't see how this story can sustain itself, though I'll ride with it for as long as it can manage.