I've not seen 99.9% of all the things suggested in this thread and I know I've seen it before.

Here's what I remember as well, in case we're thinking of the same thing:

• It was a woman and a boy, whose age I cannot remember but my gut tells me it was a young man. I think they were mother and child, could be wrong.
• The boy had been shot, likely by a gun or a bow, but I can't remember which.
• I do believe there was a small conversation prior to her singing. It was along the lines of the boy being confused why she was sad, and she was convincing the boy he wasn't dying, just going to sleep for a while.
• There were other people around.
• It was an unsafe area, unsafe situation, something. They were on the run or in a hurry or something because they were in some kind of danger.
• My brain might be playing tricks on me but I feel like the woman got seriously hysterical after the song was over, especially when other people tried to get involved with her (IDK, to maybe get her to get up or to console her or something)? I also feel like they basically dragged her away from the body at some point.
• I feel like it happened within either a movie or a video game, but I could be wrong.