Friend showed me her cuts

So, I was on FaceTime with my friend a few hours ago when I turn to see the screen pink, so i assumed it was her fingers. This was like two hours after I started the call, she told me to call her. Then she moves her camera from her leg and I realize that they're cuts. Then she puts the camera down again for a second and comes back to show a fresh cut. Then she says "Hello!" In a cheerful voice. Then she puts her tablet down and I hear running water. Then she just continues our normal conversation. She ended the call and we texted a bit and she left and just texted me now. What do I do? Thanks for any advice.
EDIT: I did know that she did, but I thought that she stopped. Also, I do this as well so I know how she feels. I just don't know how to bring it up or help her or anything.