rachylou, thank you for an interesting, thougt-provoking comment. You are right--many people care a lot about others' children. They certainly deserve more attention and praise than they usually get. Two of the most important persons in my childhood never got children of their own. I am ever grateful for what they did for me and my family, and I am glad I used opportunities to thank them in several ways before they died.
By the way, Mother's Day (and Father's Day, for that matter) is celebrated on (very) different dates around the globe ...
As for myself and my family, we don't celebrate any of those days. We try to make every day a happy day with love, care, laughter--
and often surprises in the form of flowers, small gifts, or someone's favourite food. I call my old parents every day, and we enjoy talking.