The proper protocol is to tell a TRUSTED ADULT, and if she is also suicidal or you believe her safety is at risk, call 911 and tell them. They will come and assess her for risk and if she is at risk, they might put her on something called a 5150 where she will be given help. At first, she may dislike you for telling on her, but it is the right thing to do and means you care about her. Eventually she will realize. Calling 911 is NOT overreacting. This is coming from a cutter who has been on many 5150s before.
