The Eluna Network has a variety of kid's grief camps that focus on positive reinforcement, protective factors and useful tools that bring comfort, hope and healing to support children and families as they navigate their way through the darkness.
Here is a video of their programs and you can get more information here: https://elunanetwork.org/media/moyer-foundation-program-video-featuring-human-by-christina-perri
For more children's grief resources, check out their resource center: https://elunanetwork.org/resources/category/childhood-grief