Mab and Titania aren't killers

"And so you did. More truly than if you'd exchanged words."
I frowned at her and thought through what I knew, and what I'd learned on my trip to the Stone Table. "Mab shouldn't be in any hurry. If Summer is missing her Knight, Winter has the edge if they wait. There's no need to take the Table."
"Yes."
"But Summer is moving to protect the Table. That means Titania thinks someone in Winter did it. But if Mab is responding instead of waiting, it means ..." I frowned. "It means she isn't sure why Summer is moving. She's just checking Titania's advance. And that means that she isn't sure whodunit, either."
"Simplistic," Lea said. "But accurate enough reasoning, poppet. Such are the thoughts of the Queens of the Sidhe." She looked out across the lake. "Your sun will rise in some little time. When once again it sets, the war will begin. In a balanced Court, it would mean, perhaps, little of great consequence to the mortal world. But that balance is gone. If it is not restored, child, imagine what might happen."


Summer Knight Chapter 23, Page 277