Molly is fourteen when it happens and for months she doesn't tell anyone. She shouldn't have been out so late, anyway, shouldn't have gone near the Forest, shouldn't have stopped when he asked her the time and shouldn't, shouldn't, shouldn't have let him touch her, because by the time he'd gotten that close there was no going back. He was too powerful, and she knew – could sense – the dark magic within him.
It is some years later before she makes the connection between him and the Dark Lord, and even then she will not speak to anyone of it except for Arthur, and Professor Dumbledore, but he knows already, as he always seems to.
When the child is born its hair is red, like hers, and Dumbledore helps her find a home for it, among Muggles. He reassures her that they know about their world, that they will be prepared if the child – a little girl, a darling little girl that it hurts her to have to give away – is selected for Hogwarts.
She kisses her daughter goodbye before handing her over to the Muggles – they seem like lovely people, and she knows, she knows that this is the right thing, she just wishes it didn't hurt so much.
The child grows up tall, like her father, and she has his eyes – green, not that anyone would know now, for when the Dark Lord returns, he is so physically altered that few would make the connection. And she has her mother's hair, after all, and when she has a baby of her own, everyone says that he looks like his father, and no one mentions, because no one knows, that he resembles his grandfather, too.
But Molly knows. And watches. And waits.