--[x] Go. Speak with her. Listen to what she has to say, and explain the situation. The Matsu have a sense of "honor" that is, at times, troublesome and even objectionable, and you will not dispute that. On the other hand, you are about to use that sense of honor to send them off to war against the glass golems, where a great many of them will die in your service, and in protecting Rokugan itself. You are doing what you can, where you can, but you have to work with what you have, and right now, what the Empire needs is to have the Matsu honor pointing them at the enemy rather than tearing them apart from the inside. Talk with her abotu what she suggested (not necessarily a bad idea, in other circumstances), and why it really didn't work here. Try to convince her to be willing to tender some sort of honest apology. (You are not asking your wife to lie here, or change her mind, just pick her truths, and find *something* in her behavior that she can reasonably apologize for. Check it before you go to make sure that it's the sort of thing likely to calm, rather than further enrage.)
--[x] With Kaname in tow, go speak with her. Kaname is to make whatever apology appropriate (to which we will add some small apology of our own, if we can do so gracefully) and then leave (unless she *wants* to stay... though if she does, she should not offer other radical suggestions until we are done). Then we ask for Satomi's side of things, and what she wants. While we're at it, we would like to know any other concerns that the Matsu have that she might know of.
--[x] Have the appropriate channels let her know when we'll be dropping by to speak with her. If a few other members of her delegation happen to be visiting her in the infirmary at the time, and perhaps wish to offer limited contributions of their own, that is also acceptable, but this is meant to be primarily a discussion between ourselves and our vassal.
--[x] Agree to nothing. Be prepared to pull out the appropriate level of the "I am the Emperor, and that borders on rudeness" card (level 1: raised eyebrow) if she tries to push the conversation too far in a hostile direction, but be willing to put it right back down again once she backs off. We understand that this is a difficult time for her.
[X] Write in: Refuse to see either of them before the other. Have both parties be politely disarmed (cleaning swords), then put into a room opposite of each otherand appear in full force. Currently, they are rebelling against your(ancestors) clan and your imperial majesty and making them feel as miserable as they should is a necessity