Peg Bracken's I Hate to Cook books (of which there are a number) have some sections devoted to the single life, and are written by an American so the cultural references will be right. It is worth mentioning that one doesn't have to only cook one portion at a time, cooking for four and a handy freezer is a great labour-saving combination.
If you can get hold of William Rushton's "Superpig" this has sections related to cuisine, and a number of other relevant household survival tips which may prove helpful. It is also a humorous work, with some eccentric illustrations, which just might lighten your friend's load a little at a trying time.