I'm not sure what I'm hoping for from this thread. Perhaps someone will have had a vaguely similar experience.
Today I said goodbye to a child I know, as she's moving back to her home country. We had a very special relationship as she has selective mutism and "selected" to talk to me. I am not a psychologist or therapist, but was the only person she would chat freely to.
I don't have children myself and am very sad that I probably won't see her again. I think she would like to keep in touch, but I am aware that may not happen due to her age. I'll miss her.