Mama is overseas so Angel has been sleeping on her own. Tonight she came to my study room at 10:30pm (1 hour past her bed time), with tears in her eyes telling me that she feels kind of lonely and she's afraid of the dark.
So I brought her back to bed, patted her back, and sang to her. In the end we both fell asleep.
This reminds me of the time when she was just a baby, we used to do the exact same thing to make her sleep. How time flies.