Nothing but being there for her will help. Stop by once a day and help her with simple things he would do for her like bringing dinner or being with her when going out for groceries. Fixing things that broke. Gathering all her momentoes of their life together and making a book of pictures, designing a shadowbox of trinkets he bought for her, and setting up projects you can do together that will allow her to remember all of the good times they had in the past.