When Molly Brown (excuse me, Margaret) boards at Cherbourg, she's carrying two Louis Vuitton suitcases and a train case. On this train case is a sticker. What sticker is that? It doesn't look like a White Star Line label that I can see on the internet.
Could have been from a train (the only way to get to Cherbourg at the time ?) , tourist attraction, a hotel or from a previous journey on another steamship line ? Although there are now close to 400 "nitpicks" on "Titanic (1997)" this might have been something that Cameron came up with on research ?
Mrs. J.J. Brown (who was definitely not known as "Molly" as depicted in the movie) did travel a lot and and had traveled rather extensively before boarding Titanic.