Think I have an employee being abused

I've noticed recently that one of my store associates is coming into work with bruises peeking out of her sleeves and up the back of her neck - like someone has grabbed her very hard. I've previously pulled her aside and generally asked her if everything is okay, and she just looks at me blankly and says she's fine. Last week she was wearing a flowy top, but when she bent down to unpack a box, I could see her lower back was black and blue. I tried again. I pulled her aside and asked how she was doing, telling her I noticed her back, and asked if she wanted to take the afternoon to go see a doctor or if there was anything I could do to help. She looked at me blankly again and told me she was fine. I said if she ever wanted to talk to someone that was not her store manager, she should, and I gave her the number for our EAP hotline. I mentioned this to our district manager, who is a man, and he told me to tread lightly and that if I've asked twice and she said she's fine, to leave it alone. Have I actually done enough?