She is an actor, though she does not perform on the stage. She acts every day. She says her lines and keeps to the script. The world is her stage and she plays the part as well as she can. Sometimes she slips up. She stumbles on her lines. She misses her cue. But she plays a supporting character and everyone is watching the stars.

She smiles and laughs when she is supposed to. She steps into the body of That Girl, who everyone knows. She becomes That Girl. She thinks like That Girl. She acts and talks like That Girl. She works hard to convince everyone that she is the part she plays. She does not deviate from the script. Deviation would bring disaster.
She always watches from the background in That Girl's mind, harshly critiquing her own performance. She wears the makeup and follows the script. No one can tell that she is an actor, but, of course, no one really looks past the makeup and hair, the costume and the doctored expressions on Her face. She cannot cry. Her makeup might run. Mother, father, brother. Aunts, uncles, cousins. Teachers, friends, peers. They all believe her performance.
Only two people in the world know her without her mask. One is the friend she sees every day, the friend who can read her face like a book because she has seen it unguarded, tears running from the eyes as all pretenses are dropped. The friend she called in the middle of the night when she contemplated running away from the life of That Girl. The friend who knows her so well and can distinguish between her and That Girl.
The other is the friend she never sees, the friend who she writes to and sees through words and type. This friend does not know That Girl because she is not a part of That Girl's life. She only sees the girl who plays the part. She rages to her friend and her friend rants back. They are not involved in each other's lives, but they are always support for the other.
She has two friends who know her without the mask. They know her better than she knows herself. She has been playing the part for so many years; she has begun to forget herself in the face of That Girl. She is an actor. She plays a part. Her whole world is her stage. The stage is her world.