Needle Marks on Laura's Hand

This is a picture of Laura from back 2 years ago in September 2018. Yes she used a bunny selfie in picture but that a side look at her hand. The spots which appears to be marks with the use of needles from injecting heroin. I marked the spots on the picture with little arrows. I asked her once about that she was like a slight nervous for a min. I said what's that ? or what's that on your hand ? she said their just scars. I always thought drug or heroin addicts shoot their selves up in just their arms. I was told once by a drug hotline back 3 years ago in 2017 the guy I spoke with on the phone said it can be between the toes or whatever other stuff he said but as long as they can get the vein. He didn't want me to let her in my place because of me knowing what she is doing thinks if she would of died in my apt I would feel guilty and start doing it too. I told him I'm not going to do it. I just called that number to get advice is all and that was it.