I think the reason why the prophet said she will not be the successor is because she has the healing powers. Maybe because of that, they wanted her to be some sort of godly figure rather than a retainer for the prince? This is just a random theory I had and I'm probably wrong ( ̄∇ ̄")
To me the "prophet" looked really suspicious... If a fight over succession could blow up this badly, there must have been fights in the background even before.
Maybe her powers got leaked and someone wants to tear apart the OP siblings and OP prince (and the probably OP not-yet-known-servant as well).
Spoilers.........................................................
I cant wait until she divorces that asshole and marries claude
Answer
Yes...but it'll be when she is 27(?) Years old because that "husband" asked her if she would like to marry him for real and she said no and left to get the divorce paper and then afterward she went to the house where her grandmother's land(?) Left for her and met claude again as they did as kids ...after that......they both went to ask her father's permission and the father began to felt guilty for what he had done for her so in the end she married claude and soon afterward she still continues to live in the attic of her new home hence the title is what is called "the duchess lives in the attic" x3










God Tomoki is so annoying....just give me more of the mc Σ(  ̄□ ̄||)