DEAR HARRIETTE: One of my best friends lost both of her parents this year, within six months of each other. They were well into their 90s, but still, the loss has been devastating for her. I am doing my best to comfort her, but sometimes I am at a loss. I still have my mother, who is in her mid-90s. I feel awkward talking about her now. I don't want to rub it in that my mother is alive and hers is…