She began walking the mirrors as a child, swapping worlds with her other selves. She became ambidextrous before she knew it was unusual.
She was in her teens when she realised nobody else could move through mirrors like she did. And that not all loved mirrors like she did.
She tried to see like they did, to see the reflected world, not the one on the other side. To see herself, not her other. She succeeded.
She saw herself. She seemed unreal, strange to her. Faintly, behind her own reflection, she saw her other self look surprised, afraid.
As she stared, completely still, she saw her other self lift a hand and touch the mirror. And then she faded, and she saw only herself.
It has been a long time now; she is not always sure it was not just a childhood game, a make-believe. She tries to believe it was real.
She looks in mirrors, and tucks her hair away with either hand. One day, she sees her other self use the other hand. And they smile.