I really got to know my baby sister when she was 12 and I was 18. She was in crisis because she was being bullied at school by all her supposed 'friends'; I was in mental health crisis (which I didn't know at the time) and drug and alcohol withdrawal (which I also did not understand). I had agoraphobia and spent a lot of time in my room with the light shaded so it was very dim. She used to come in every night and play cards with me and we'd talk. She'd tell me about all the things they were doing to her at school and I would build her up and tell her not to believe it because it wasn't true, and they were only mean to her because they had low-self esteem and that she was better than them. We developed a Friday night routine of going to the general store and buying little bags of penny candies, and then going back home, lighting candles in my room, laying across the bed and watching Buffy the Vampire Slayer on my old black and white TV.
For years afterward, once I moved out of the house, apparently she kept my room exactly as it was because going in there and having memories of me was the only time she felt safe.