Sonia did not read the whole contract since it was long. But it was stated there that Arabella and Ferdinand were given full custody of Dimo until he decided to return to their duchy completely and not return to Valeria.
Dimo would still be under their custody even if he returned home to Olivier for vacation.
Thus, they could still take legal action against anything committed against him even if he is in Olivier if he had not decided to fully leave Valeria yet.
It was for Dimo's safety, so Duke Olivier had agreed to it even though he was a bit wary about it at first.
[I'll be able to see father again, right?] Dimo sniffed and waved to his father one last time before Rendell scooped him up and settled him into the carriage.
Rendell had to do that since Dimo might trip. His eyes were all red and puffy from so much crying. He might trip and fall so it was safer to carry him into the carriage.