She's tired of the cycle of Nate wanting to "protect" her in his obsession of adventuring by lying to her. They've gone through this cycle before. Also, this went on for weeks. Nate did her so wrong. She would've initially opposed it as she did in his search for Ubar against the Hermetic Order but would've gladly went to the Auction and everywhere else in his search for Avery's treasure had he simply told him about it as well as Sam's existence.
I personally liked the Order despite the unfinished and rushed plot of 3. Marlowe had potential and I liked her in the first half of the game. Sadly, post-Yemen, the story got rushed and her death was stupid. Talbot btw is my favorite villain overall so there's bias there lol. My three reasons for liking him: his elegance (He wears a suit and dress shoes EVERYWHERE lol, even in the desert he has at least a dress shirt and slacks), his cunning, and his smoke and mirrors magician arc. I also find it fascinating that him and Marlowe basically mirror Nate's and Sully's parent-son style bond.
Heroes: Chloe, Sam, Elena, and Sully.
Villains: Talbot, Asav, Lazarevic, Nadine, and Roman