This is Your Life Harriet Chance by Jonathan Evison

Harriet learns of the cruise after her husband's death and decides to take the paid for cruise to Alaska anyway. She is dreaming of Bernard and see him everywhere- literally, but others think she is slipping. It should come as no surprise when her daughter end up on the cruise and Harriet discovers another side to Bernard and his secret life. Harriet reflects on her life, her marriage and the Bernard she knew and didn't know and comes out stronger at the end. Interesting travelouge of the cruise itself and Alaska's wonders.
You will giggle, you will cry and you will admire Harriet's style.