Chambrea is the second boss in Luigi's Mansion 3. She is the maid of The Last Resort. She is fought on the fifth floor where Professor E. Gadd's briefcase is located. When she is captured, you will receive the button for the third floor.
When you reach room 508, Chambrea will be dusting the room. When she finds the briefcase, she will take it. To attack her, aim the Suction Shot at the briefcase. Then, slam the ghost, draining 20 HP for each slam. After a few slams, Chambrea will leave the room. You can see what room she went to by using the Dark-Light Device.