Often being in control of something and doing it 'for attention' is a blazing, light up sign screaming 'HELP'.
This. Sorry if the next bit goes too far (TW)
I was told I was attention seeking for cutting as a teen. Did I need attention? Yes, I needed someone to actually ask if I was ok, to let me talk about what was going on at home, about my past. (I also now understand it was a way of dealing with difficulties caused by autism and ADHD - sensory regulation and dopamine seeking.)
In the end I felt pushed further and further to the extent that I was in ICU from an overdose. I didn’t actually want to die, but I nearly did. And even then it took another minor OD and deeper cuts before I was hospitalised.
Once in the hospital I found out the ward manager thought self harmers were “manipulative, attention seeking and a waste of [hospital] space”. The way I was treated even on the ward has stayed with me, in a bad way. I have a deep fear of being seen as manipulative and needy when I’m struggling.
So the idea that it’s just for attention is widely held. But I really think that must be incredibly rare, and even if the aim is to get attention then there is a reason that need is so bad they are willing to hurt themselves, like BPD/EUPD suggested by others. Even in “outbreaks” in schools where teens are exploring it, I don’t think attention in the negative sense is what it’s about.
Attention = care, love, HELP.
I really hope your sister can get some help 💐