If a parent loses his/her only child, does he/she still celebrate father's day/mother's day?
This person will still celebrate these days without a child. This will remind them how they would be also be celebrated by that kid. This person will also celebrate his/her parents on these days and also be happy for other parents.
Absolutely. If you loved and cared for a child whether they be in the womb or 28, alive or passed on, you will always be a parent.
as a memory you should
I think for some people it's a day to mourn.
My mother passed away when I was young, and after that, my grandmother did not like Mother's Day. It depends on the individual.