If it makes it easier for you to write it, keep in mind that not everyone self-harms for the same reasons. Her reasons need not be yours. Her feelings need not be yours. Even if her reasons are yours, her feelings need not be the exact same.
I used to self-harm because I was desperate to feel anything and pain was better than the all-consuming numbness I was otherwise feeling. Self-harming made me feel alive. I used to self-harm because feeling something, even pain, signified to me that I was still standing. Damaged but not broken. My scars are neither badges of honour nor of shame but simply a part of me--relics of something that at the time helped me survive just as much as my lungs or heart do.
I neither hide them nor call attention to them. They just are and if someone sees them it is not any more relevant to me than if anyone sees a scar that wasn't self-caused.
One of my friends self-harmed out of guilt, because he felt unworthy, felt he had to punish himself for what he saw as transgressions, flaws, sins. To him, each scar represented shame and guilt. Probably still does, even if I haven't spoken him for years. He hid his scars and became very upset if someone noticed them.
A good online friend told me that she used to, for a relatively short time (years before I knew her), self-harm as a plea for help. Although she hid the wounds and scars, part of her wished for someone to see them. To notice that something was wrong, that she needed help. She told me that looking back, she was getting more and more sloppy in hiding them not out of complacency but because she wanted them to be seen; wished for someone to intervene and get her the help she was at that time unable to ask for.