For this prompt:
The knocking started at the age of five. Natalie thought it was her mommy, then her dog Bucks being silly but it continued and one day, she suddenly realized that the knocking sound was coming from the mirror.
It was her, right down to her white shorts with the peanut butter stains and the messy ponytail of dark brown hair and the scar on her chin from when she fell as a toddler. Mirror Natalie had grinned when she looked and waved, so being five, she waved back, seeing another friend. Mirror Natalie became a playmate when she was left to her own devices as her mommy and daddy entertained business associates and friends every Friday and Saturday night. They had decided soon after her birth that children were too much work so Natalie had Bucks, her dolls and her reflection.
At ten, Bucks died. Fell right down and died and her mother dryly joked that the dog was so stupid, he must’ve become frightened by his own reflection. Natalie could’ve sworn she saw Bucks’ tale wagging behind Mirror Natalie’s bed a few days later.
Natalie suspected she might be going mad around the age of thirteen and Mirror Natalie still moved about in the mirror. She could never hear her but Mirror Natalie continued to speak at her. Sometimes the pantomiming worked, most of the time it didn’t. She chose not to tell anyone, she was sure her mother would send her to the mental ward her aunt Sonia was at.
At seventeen, Natalie got her first boyfriend and realized her Mirror was now able to travel, showing up in her boyfriend’s bedroom mirror after they’ve had sex for the first time. She was startled but even more so when Mirror Natalie’s head tilted slightly, never breaking her stare as she smiled at Natalie. Mirror Natalie wore a dark red lipstick she wasn’t, her eyes a near-black to her green.
Natalie stops staring at her reflection for long periods.
Her aunt Sonia sits at the Gladesdale Mental Ward, staring right ahead, her gaze blank. Her mother said Sonia died on her eighteenth birthday, they had found her on the floor of her bedroom, croaking hoarsely but never speaking again. Natalie begins to cover the mirrors.
On her eighteenth birthday, Natalie’s boyfriend takes her to the movies because there are no mirrors there. When she goes home, she keeps her head down as she brushes her teeth even as her reflection knocks and knocks. Her shriek when the mirror cracks echoes in the empty house.
The blanket over her full-length mirror blows as she changes, even though the window is closed. There is a sharp knock and she turns, screaming at the sight of her reflection, just an inch from her. She stumbles back as her reflection shoves her hard and instead of hitting the mirror, she goes right through it.
Natalie’s new home is cold and silent, too silent. Bucks barks at her but no sound comes out. She bangs on the mirror but no sound echoes, not as she screams for her mother as she walks into her old room and collects her hair straightener, not as she bangs when her reflection watches television with her old friends.
Natalie starts to think all hope is lost, that no one will never see her. That is, until her reflection meets her gaze while applying her lipstick, and to Natalie’s horror, she winks.