A lot may depend on how old your child is, and how close they were to the person who passed. If it wasn't someone they saw on a regular basis, it may not have hit them yet, that the person is no longer there.
I am 16 & when my EXTREMELY close grandpa died i only cried @ the funneral and the night of... My point is that i may deal w it differantly than say my grandma, we all have our own ways. DONT make the kid cry because of status quo, plz!
We all handle it differently. They may grieve in private and you may not know. My daughter was 7 when her Dad died and she cried the night of his death, got angry with me and grew up to be a beautiful, healthy, happy adult who still has the memories and pictures of her Dad 18 years later