Sleep Trials: Science Fiction

They hadn't thought it out when they got their yet-unborn daughter into the trials for gene therapy to provide a short sleeper. Who wouldn't want to sleep only four hours a night? Once she was born, they rapidly figured out the answer was, "Us!" By then it was too late, though, and they did love their daughter, despite her annoying habit of being bright and chipper at 2 A.M. They hired a progression of nannies, to no effect until they settled on one woman who smiled a lot and seemed bright and said she had an amazing collection of lullabies. They didn't figure out she was doping the child with a little gin until--

Inspiration: News article showing that it's a gene variant that allows some people to feel fine on 6 hours of sleep. (I am not one of those people.)
Story Potential: Low.
Notes: Nancy Kress already did this, much better than I could.