Facebook chief operating officer Sheryl Sandberg says that until her husband's death, she never realised how hard it is to be a single parent.
She says in a touching Mother's Day weekend Facebook post that odds are stacked against single mums.
"For me, this is still a new and unfamiliar world. Before, I did not quite get it. I did not really get how hard it is to succeed at work when you are overwhelmed at home," she writes.
"I did not understand how often I would look at my son's or daughter's crying face and not know how to stop the tears. How often situations would come up that Dave and I had never talked about and that I did not know how to handle on my own."