You may know her as the bright-eyed Victorian beauty popularized by the American Girl series, but by 1912 Samantha Parkington was a seductive 18-year-old heiress traveling home from her European Grand Tour. Educated, liberated, and uninhibited, she had turned heads across the continent, but not until the voyage home did she meet her match in the capable arms of the son of the 15th Duke of Denver, 22-year-old Lord Peter Wimsey. (Peter, a recent Oxford graduate, has been sent to America by his uncle to forget the flighty but beautiful Barbara.) The ship on which their passions ignite? A vessel as immense as their desires, the majestic, unsinkable Titanic.
Further development from the comments:
Lord Peter puts the ladies in a lifeboat, but Samantha gets out to rescue steerage passengers because she's a crusader and doesn't believe in steerage. (Samantha's aunt was also liberated; hence the lack of oversight.) Peter jumps off the ship and ends up standing on top of an upside down lifeboat (historically accurate: Collapsible B), while Samantha dies because I say so.
The girls were alternately fascinated and disgusted, which is probably most people's reaction to fan fiction.