What’s the colored sentence mean?
She sat in her room on the old couch my parents had given up on and worked on hardening herself. Take deep breaths and hold them. Try to stay still for longer and longer periods of time. Make yourself small and like a stone. Curl the edges of yourself up and fold them under where no one can see.
It is not a literal action, Mohammad. It is metaphorical: 'withdraw your personality from its interface with other personalities', or something similar.