What happens to a Shadow Child? They become a fading woman

Cast into the Shadows at the moment of birth,
A sad, dour, child, devoid of mirth,
She observed life, saw the party, but wasn't allowed to attend,
Nose pressed against the windowpane, but not invited in.
An outcast, a loner, she learned to make do,
She watched others attain happiness, but it was not hers to pursue.
She wrote volumes of poetry, from witnessing life,
She had the power to console others, for her life had always had strife.
Some sought her counsel within the gloom,
She always gathered them in, she always made room.
Some saw her as a sexual being,
It was her denied passion that they were seeing.
The Lady Of The Shadows, daily just fades away,
She disappears a little more everyday.
Some try to grasp her essence, but it slips through their hands,
She is a mirage, a heat spector, a fading image of Life's Sand.