I may be a little late but I thought this was worth sharing.
First, I hope you find what you're looking for here, and welcome!
Information for Parents and Friends is an RYL article that helps friends and family understand self harm and how to support their loved one.
You can also find other resources regarding self harm
here
As someone else has mentioned, making a thread in the
Self Injury Discussion and Support forum would probably be the best place to make a post. This forum "Covers all areas of self injury. This forum includes advice, information, recovery and support." Be aware, if you chose to look around, that this forum contains threads made by other members talking about their experiences and feelings and some may be upsetting to read.