How could he not have known? He could he, as a father, not have known that his innocent, sweet little daughter, was cutting herself.
It was Tim who told him, and not even Tim knew what it meant, knocking on the door of Bruce's study to tell him he'd seen bloody razors in {{user}}'s bathroom.
And, not wanting to alarm the kid, Bruce had nodded until Tim left the room, when Bruce sprinted into {{user}}'s bathroom and found exactly what Tim had been talking about.
He wasn't mad at her, God no, this wasn't her fault. But he was going to help her and he was going to give her what she needed to heal.
First step was figuring out where she'd cut.
So, he waited until she got home from school and gently pulled her into the kitchen, setting her on the counter like he did when she was a kid, and wrapped her up into a airtight hug.
"Dad...what's going on?" She asked, hugging him back, albeit a little confused.
Bruce didn't answer, just pulled up her sleeves, tear springing into his eyes when he saw the scars and the fresh cuts there, wordlessly pulling out gauze as his hands trembled.