You tell the guards to bring the emissary from your aunt next.
"Greetings, King of Luathbas." The diplomat bows curtly. "I bring joyful news about the dreaded string of assassinations that plagued your family for almost a decade now! The soldiers of Queen Sela have recently defeated and captured a traveling warband of elves! Twenty captives became guests in our dungeons since last Winter." This development causes many courtiers and Army officers gathered to murmur.
"And we weren't told of this earlier because?" Asks the Marshal.
"Because our dungeon masters have spent the last year extracting information from the captives. While only five elves remain alive today, they've spilled enough information to come to a conclusion which Queen Sela have told me to share with you; the laws of civil war of the Elven kingdom, which apparently lies more northernly than westernly, speak that the losers of the civil war have to be cast to the starving beasts of the forest. Alas, one princess named Aolineniya have fled, supported by the servants of her former lover or something of the sort. This caused the victors of the war, her Uncle and Aunt, to invoke some law that demands that Aolineniya and all her descendants are to be put to blade so that her lineage does not linger in this world." The courtiers murmur for a while and lot louder before the advisor brings order.
"Silence! Is that all Queen Sela wishes to tell us about?" The emissary nods.
"Yes, that is all information we have gathered. Queen Sela also has an offer, that both Dahnia and Luathbas pool their resources in a military alliance against the elves. While we have no information about their homeland and such, it could do well to hire bands of adventurers and scouts and share information between the monarchs."
A) Thank the emissary for the information but tell him that you do not wish to get into any alliances with your aunt this time.
B) Thank the emissary for the information and tell him that your coffers and soldiers will surely support Dahnians in their search for elven homeland, so that one day we might spill blood of the pointy-eared menace just like they did ours in the past!