I have done a search and can't see that this has ever been posted about in here. In fact, frustratingly I actually can't find very much information about this mystery online!
Marie Empress was born Mary Ann Louisa Taylor in Birmingham, England in 1884. She started acting on the British vaudeville stage in the 1900s before acting in silent films where she often played "vamps".
The cruise liner RMS Orduña left Liverpool on 16 October 1919. It stopped in Halifax, NS and then continued to New York. When it arrived in NY, Marie Empress was nowhere to be seen. Her belongings were still in her stateroom and none of the 1,000+ passengers and crew saw her leave the ship.
On the last evening at sea (26 October 1919), a stewardess brought dinner to Empress's stateroom and later returned to take the dishes at 6.30pm, when Empress asked for sandwiches to be delivered at 9.30pm. When the stewardess returned, Empress wasn't there. When she checked the room in the morning, the food had not been touched and the bed had not been slept in, so it seems Empress disappeared sometime between 6.30pm and 9.30pm on the evening of the 26th.
Did she jump off? The only porthole in the stateroom was too small for her to have squeezed through. She would have had to walk through numerous corridors and salons full of passengers and crew to get to a deck, which no one saw her do. Empress was a woman who would have been noticed as she was very striking and bubbly. No one seems to have seen her at all that evening besides the stewardess who was serving her.
For a while, the press explained it away as a publicity stunt. Empress had pulled several of these during her career, making it possible this was just another one. However, no one ever claimed her trunks.
Unfortunately, none of her films or recordings survive, only old press clippings. Her background is just as mysterious as her disappearance. No one seemed to know very much about her. She was declared dead in 1921. The cause of death was "jumped overboard, presumed drowned".
The only sure thing is that she wasn't seen again.
Link to source: The Silent Film Star Who Vanished Without a Trace