SOLVED. Trying to remember a romance novel's name about a widow. [s]

[Yubin]

A widow received a large amount of letters from her husband, which he wrote while he was dying. She needs to read one everyday, in order to help her through the loss.

Dying to remember the name of the book, your help is greatly appreciated.

[Marie]

That's the plot of the movie P.S. I Love You, which I know is based on a book.

[Yubin]

you are the best

[Juels]

Here's the link for Marie's suggestion

P.S. I Love You by Cecelia Ahern