Lilia burns through a wand of Shrink Item and her staff of Dimension Door, collecting the bodies of delegates and their families and anyone else she spots in the course of that work who will predictably be resurrected, either by the archmages or by the Church of Abadar. (Yes, she can recognize most delegates by sight even when they've been bludgeoned by a mob. What exactly do you imagine she has spent the time since the convention began doing?)
Probably it could have waited for morning, and be done with the expenditure of fewer resources, but if she were among her mother's enemies she'd show up in the aftermath to wreak more havoc here, to double down on the extraordinary expense they've just imposed on the crown, and one shouldn't assume one's enemies are all idiots just because they keep acting that way. She fills two Bags of Holding, and arrives at the palace dry, angry, and wearing the face of Riudare. (It's not personal, or not very personal. She just needed a face that'd get her a prompt audience with the Queen without sparking rumors the Queen is working with Cheliax's Evil old spymaster.)
Even mediocre palace security would think to check for illusions, but she's Mind Blanked and none are apparent, and security hasn't really been a priority in setting up the Queen's administration, what with how it wouldn't keep out Geb anyways and nothing lesser is a threat to the Queen's personal safety. And she's the best liar in the world. They let the Queen know that Riudare is here requesting an audience.