I can’t remember if I mentioned it in here before, but there’s a book called “The Invisible Leash” that we found really helped when our dog passed away. Our daughter was 3 at the time and 2 years later she still talks about the invisible leash to our dog Ringo.
https://www.indigo.ca/en-ca/the-invi...E&gclsrc=aw.ds
Fair warning, reading this book may cause a lot of tears for the adults…haha.