A young woman with magenta-streaked hair stands in her bathroom, speaking to a webcam. In a hushed tone, she chews over a thorny problem of young adulthood: how to apply full evening makeup when you’re already inebriated from drinking all day?She begins her tutorial by wielding that totem of collegiate binge drinking everywhere: a red plastic Solo Cup. One jump cut later (after a “Law and Order: S.V.U.” drinking game), she re-emerges, thoroughly intoxicated. She misapplies a gob of glue. It dangles from a false eyelash. She lines her lips with a black pencil.“It doesn’t matter what color it is, ’cause you’re gonna blend it,” she slurs, batting her eye glue. “Don’t let this scare you.”The video, titled “Drunk Makeup Tutorial,” is completely awesome to some, bewildering to others — and above all, classic Jenna Marbles, another installment from a reigning queen of YouTube. The episode has been viewed 14.6 million times.While few people older than 30 probably know who Jenna Marbles is, her popularity is unquestioned among teenage girls who live on the Internet. She has more Facebook fans than Jennifer Lawrence, more Twitter followers than Fox News and more Instagram friends than Oprah. Her weekly videos on topics as quotidian as “What Girls Do in the Bathroom in the Morning,” “My Favorite Dance Moves” and “I Hate Being a Grown Up,” place her in an elite club of more than one billion YouTube views, with more than eight million subscribers and growing.“My perspective is to think, ‘I just have a lot of Internet friends,’ ” said Jenna Marbles, 26, whose real name is Jenna Mourey (Marbles is the name of her Chihuahua). She acknowledges it is an odd kind of celebrity. She is a D.I.Y. digital entertainer who conceives of, stars in, shoots, edits and uploads her own videos — often in a single day.