Towel Day by LastScorpion an "And They All Lived Happily Ever After" Liona OTP ficlet
The littlest Luthor was trouble from Day One -- a breech presentation, she was the only one of Lana's daughters to require more than fifteen hours of labor.
Secretly, Lionel thought she was the most like Lex.
Lana thought she was the most like Lionel.
When she was three years old, Lenore managed to sneak away from her parents and sisters (who watched one another like vengeful tattle-tales, at all hours of the day and night) on a weekend outing to the Metropolis Museum of Fine Art. It was a day crowded with incident, including Lionel firing the entire museum security staff and Lana fainting dead away (possibly as a ruse to distract her husband from the unwanted realization that he actually couldn't fire the entire museum security staff).
That was the first time (but far, far from the last) that she was saved by Superman. Even he was purely unable to explain quite how his youngest (secret) sister-in-law had managed to climb twenty-five feet up into the heating/ventilation ductwork, but he was the one who heard her and got her out, and returned her to the bosom of her loving family.
Laci, Lena, and Letitia all scolded her viciously, but Lana swept her up into her arms, and Lionel embraced them both. Dozens of photographers got the shot.
After that day, though, she stubbornly refused to answer to Lenore. Her favorite stories were, bizarrely enough, Edgar Allen Poe rather than Greek Mythology or even Brothers Grimm (she taught herself to read at the age of two, just like Lex had done), and she stoutly maintained that she wasn't Lost Lenore! She demanded to be known as Lorraine (realizing herself that somehow all Luthor names started with L) since that was her favorite quiche.
Over the years (A Luthor Never Backs Down!!! had seemingly been incorporated into Lenore's psyche in utero) she never changed her mind, and gradually her mother and sisters came to see things her way. Lionel never did, though, and called his youngest daughter Lenore until his dying day.
The other change that her jaunt in the ductwork wrought was that Lenore (Lorraine!) started a routine of stalking the housekeeper on laundry days, and stealing one of the big towels as soon as they came out of the dryer. She'd tie it around her neck and swoop around the premises, "saving" the soft toys and declaring herself SuperLorraine. Fortunately, Laci took no time at all to convince the middle girls that this pastime was babyish rather than cool, so there was only one little girl crashing around like a lunatic rather than four. Lana thought it was funny, but she still mostly managed to limit the SuperLorraine Hour to times when Lionel was out.
Lenore (Lorraine!) kept up the game for six years, until she figured out for herself that Superman was actually Lex's dorky husband Clark. After that, it just seemed silly.