What did she use to do this?
Did you ask her? If so what was her response?
What is her age?
Any other issues in the past or currently?
May I ask you one more question. Where do you live? (city/state)
I'm not sure if you don't feel comfortable giving me your state. I asked because there is a lot of gang activity in some states that deals with a gang called MS 13. One of my thoughts was that perhaps she is friends with someone that is involved with ms 13. My other thought was that maybe it had to do with the fact that she is 13, maybe she has some concerns about getting older, sometimes teenagers do things like this, not realizing that it can leave permanent scars. Another reason could be the start of cutting, which is a form of self injury, somewhat common among teen girls. I would check her arms, legs and stomach and keep a close eye on her if you think this might be the case. I'm going to give you some links below about cutting, but if it continues, you might want to have her see your family doctor, and see what he recommends. Most cutters will cut where it can't be seen and try to hide their wound/s, this seems to be something she wanted others to see and could be attention seeking behavior.
If you need to talk more, it costs nothing to click reply.
Thanks for that info. MS-13 is known to be in the following states Pennsylvania, New York, New Jersey, Miami, Southern California, Washington, D.C., Northern Virginia, Maryland, the Hampton Roads area of Virginia, Richmond, and Delaware. In Allentown, Harrisburg, Philadelphia, and other areas of Pennsylvania. This gang is comprised of Hispanic members, and they are very into tattoos and body modification. They tend to gravitate towards younger age teenagers as well as elementary school children. She may have made friends with someone or know someone who may be trying to enlist her, but not telling her much about the gang at all, in fact they may be treating it like a game, just to get her interested.
I'm not saying this is the case, but as you know, as parents we need to look at every aspect of a situation, and keep our minds open to any possibility until we find an answer. I wouldn't automatically accuse her of anything, just pay closer attention to what she's doing. You can click here to see more info on MS 13, some of the links have pictures. You can look through her notebooks and doodling to see if this number 13 is showing up.
Let me know if I can be of further assistance, or if you want to talk more