AN~ Edited: made canonical, added details so it's almost twice as long.
Daphne cursed under her breath and turned the sink on to wash her face for the fourth time that night. She'd never get this stuff right. Her face was a mess of gloppy mascara decorating plenty of spaces that weren't her eyelashes (the worst was her eyebrows), uneven foundation that didn't cover up her zits but caked onto the parts of her skin that were clear, bright red lip gloss that didn't stop where her lips did, uneven coon-eyes of eyeliner, highly arched unnatural eyebrows she'd tried to draw into a better shape, dark shadows on her cheeks that were a failure at contouring her face into something more elegant and less baby-round, dark red smears of blush on her cheeks, and eyeshadow that made her look like a clown- and worse than that, eyeshadow that had gotten in her one eye, making her tear up.
For the past few months, Daphne had unconsciously been mimicking her sister's actions at the same age, making nightly excursions to the bathroom to try to turn her face into something beautiful. She was too embarrassed to ask for help, and too suddenly aware of the flaws of her figure to stop trying and live with her face the way it was. Unfortunately, she was just as bad as her sister had been at putting the various kinds of goo on her face, and she was almost tempted to give up (she'd even tried to do it with a fairy godmother wand, with equally horrific results- apparently she had to know what she was doing before the wand could do it right). She never did- wouldn't have, even if she'd liked her face the way it was. It made her feel older, the makeup. And she'd never been a quitter.
The difference between Daphne's experience and Sabrina's was that there was no one to spy on her as she experimented. Puck was off traveling the world, and even if he hadn't been, he wouldn't want to watch her. She wasn't Sabrina. Basil slept as soundly as she did, and her parents weren't concerned with what their children did at night, as long as they stayed in the apartment. Sabrina- well, she thought Sabrina might know. She'd been giving her a knowing look now and again, and yesterday she'd pulled Daphne aside and told her to wipe her cheek off before she went to school. But she hadn't said anything outright, and Daphne hadn't seen her- and she'd been watching pretty closely.
So Daphne continued her nightly experiments alone and unsuccessfully.
Daphne shook the water off her hands and sighed, looking at the contents of her black bag that littered the counter. She'd give this one last try, and then she'd go back to bed. There was only so much self-inflicted pain a girl could take in one night.
The door creaked open just as she'd begun to smear her face with foundation yet again.
She spun around, dropping the makeup as she did so, sending it spilling across the floor. Sabrina stood in the bathroom doorway, a small smile on her face.
"I thought so," she said softly.
"How'd you know?" Daphne asked. She ripped several paper towels off the roll and started wiping the floor off.
"My room's across the hall and I'm a light sleeper," Sabrina said, bending down to help her. "Want me to show you how I do it?"
"Please," Daphne said, straightening and tossing the paper towels into the trash can. That she could manage just fine!
Sabrina grabbed another paper towel and began her instructions, working over her sister's face the whole time. "I can show you how to look like you're not wearing any- it's the look I usually go for, and it depends on not using too much of anything- but you'll probably want something a little more exciting than that, which isn't really my thing. So for starters, we're going to cut out the eyeliner and just use a tiny bit of mascara. Blink. And you don't want to put this on your face by itself- you need another layer underneath it, this is a finishing touch to smooth everything over. Bronze eyeshadow will make your eyes pop, without drawing attention to the fact that you've put anything on. Close your eyes."
Sabrina spent the next two hours showing her sister the ins and outs of makeup application. They started with the subtle style Sabrina tended to use, then left the bathroom for Sabrina's laptop to look at online tutorials for more adventurous styles. By the time Daphne left for school the next morning, she was made up and ready for the day. It hadn't been that humiliating to be helped, after all.