I have 2 fledging jackdaws in my garden now dead but parents still around.

Hello, I was hoping for some advice, I have had 2 grounded fledgling jackdaws in the communal garden for the for the last 2 days but unfortunately didn't make it last night and have no idea what has happened as it does not look like a cat attack. The parent jackdaws are still around and hovering over them but I am not sure if they are fully aware or whether they are in mourning. I have picked them up safely and placed them on top of a towel in a very shallow box so the parents can still see them and go to them but they are out of the way from my children's eyesight so that they are not deeply upset. I plan to bury them rather than dispose of them in a bag but my question is, how long until I would do this especially as the parents are still around? I want to be respectful to the adult jackdaws but I also do not want to upset my children by letting them see these.