D, A Nothing says we can't be the kid's regent for Cydwyl
Cydwyllian inheritance law and Cyl's court will v:
You pack the clothes, the documents, the entourage and the kids, and haul yo bodice to Cyl's side at once.
A week later, the Cydwyllian capital welcomes you. The court nobles lead you to Cyl's bed in his quarters.
He looks weak, and the healers say that while his condition is stable, and you mention to them that you have a healing stone with you that could help. The medics look at the supposedly magical item with doubt but place it by his headrest.
Cyl smiles and touches Prince Doge's cheek, and then he sighs and closes his eyes. The healers rush to his side while you, numb and terrified, are politely rushed out of the bedroom.
A while later you learn that Cyl has fallen asleep. He did you a spook! Something to berate him for when he leaves the bed.
Next morning the diplomat that is attached to Cydwyl bring you news that the Cydwyllian court has gathered and is discussing possibilities of regency, election of new King, or some other option just in case Cyl would die.
A) They're discussing future of Cydwyl without me!? Intolerable! Time to go and tell them what I think!
B) Let's send our diplomat and politely negotiate concessions just in case someone oppose Methiantese rule.
C) It's internal matter of Cydwyllian court and I'm sure they will reach a reasonable consensus.
D) Let's send our diplomat and threaten use of force if someone tries anything funny!
E) Let's send our diplomat, but only as an observer and to make sure they're aware of our presence.