Many people think that there cannot possibly be anything to laugh about when you are grieving.  However, they are missing the extremely important function in how humor allows us to vent and it helps lessen our intense feelings. Humor can be used to deal with things that seem impossible to deal with.  The most common subjects of jokes; mother-in-laws, fear of flying and hospitals are not intrinsically funny but yet we laugh at them to reduce them in size and threat. From my experience I'm convinced that laughter will help the widow get a different handle on her stress.  If the widow wants to use humor, you should go along with it as it's helping her to cope. Humor is a bit like a miracle as there have been many studies done on how laughter makes you feel better. If your friend is a widow let her learn to laugh and smile again by being sensitive to her mood and encouraging her to use humor.