I expect this pre-pub part to be the calm before the storm, with mostly funny, wholesome and reflective events happening, like various people within Ehrenfest reacting to Rozemyne's new appearance and getting ready to see her off to the Sovereignty, as well as preparations for Georgine's attack.
Considering how Ferdinand and Detlinde are bound to be married by royal decree, I feel like Georgine has to make a move, before the archduke conference starts, but I expect it to be later in this volume. I've thought about her attacking during the archduke conference, but I don't think that's likely. It would be too suspicious if she didn't show up at the archduke conference and unlike Sylvester, she has no direct teleportation into Ehrenfest, so she would need to port into Ahrensbach or Werkerstock castle and then travel to Ehrenfest via highbeast. From Clarissa we know it's possible to do that within 24 hours, but not if you want to be left in a state were you can still fight at the end. Also going missing for 24 hours from the archduke conference is also risking that Sylvester catches wind of her attack and returns to thward her plans. Not to mention you never know what kind of incidents Detlinde might cause, if left unsupervised, so leaving her alone in the Sovereignty for that long, especially now that she distanced Ferdinand, isn't a good option either.
So TL;DR, unless Georgine can find a way to postpone Ferdinand's marriage another year (or Leonzio does something to the same effect), she needs to act now. Giving Ferdinand a poison that will make him fall into a coma for long enough to miss the window for the wedding would be a good plan to win time against most nobles, but won't work on someone as cautious and experienced in surviving assassination attempts as him.