Blencathra spot on. I love my spouse, children, and grandchildren equally and differently and respond to their needs on a case by case basis that doesn't include measuring how much I love them.
Annie I do not think that you can compare and contrast the loss of a spouse and child. My DS died several years before my mother's death. My parents were devoted to each other, and my father missed my mother every day for the next 15 years until he died, but it was the loss of his DD that remained the loss that most deeply affected him for the rest of his life. Your child is flesh of your flesh, blood of your blood, it is a completely different more primal loss than the loss of a partner.