It took her a while to finally look down at her hand. She'd been so preoccupied she didn't even notice the blood pooling underneath her fingernail. Now that she thinks about it, her finger does smart a bit.
She has a bad habit of picking at the skin around her nail--searching for a loose end that she can tear off. And once she's done it, she wonders why and vows never to do it again.
She will no doubt do it again.