It's an interesting topic, this entire exchange here.
What K asked is also interesting - my opinion is this: IF this woman is truly delusional, then she is using the delusion for some psychological means. While you do not want to play along with her, you also do not want to CONFRONT her with too much aggressive reality to PROVE to her that she is not dead. Anyone in a real delusion can instantly take any evidence to the contrary and turn it around to somehow fit in with their delusion. Do not try to FORCE her out of her beliefs, just tell her you know it's not true and then listen to her and try to help her feel calmer.
But...I'm not sure at all that you're really dealing with delusion here.
There is a very important difference between how therapists (or someone in training to be one, etc.) react to symptoms and how a concerned friend (or friend of a friend) reacts. And I think it's USEFUL to hear these differences - it can give you insights into the entire production of mental health/help, etc.
To the ordinary person, the most distressing piece of information in your posts is that this poor woman is under the delusion that she is dead! That is certainly the most dramatic fact, and it sounds so scary and it is very easy to think it's an EMERGENCY because it is just so "weird."
But unless someone is overdosing on pills or standing on a ledge (or holding a gun to somebody's head), it is better to NOT react in emergency mode. The patient is symptomatic, not stupid, lol.....and the more frantic the people AROUND her become, the more she will (i) panic in response; or (ii) feel validated if her goal is to incite lots of activity.
There is NOTHING that a regular person can do to help a delusional friend not be delusional. NOTHING. So your friend who wants to help needs to either talk to the hubby, call a family member of the patient, or just sit and talk and listen to the patient and try to help her get calm enough to maybe consider talking to a doctor. But there is nothing a doctor can do TO HER - they can offer meds and if she wants them, she'll take them - but often delusional patients won't take medication as it feeds right into their DELUSIONS!
I still believe that the larger issue here, larger than this belief that she's dead, is how functional was she even BEFORE all this? You said "she went back to her idiot husband" which makes me think she has a history of drama - leaving a very bad marriage, and maybe getting lots of support from other people telling her to leave him,and then turning aroudn and going back to him when she has no one to take care of her.
IF that is partly at work here, if this is a person who has lots of emotional ups and downs and life dramas and gets other people invovled trying to "save her" and then keeps messing herself up more and more.....there is NO quick fix and the least of her problems is this new delusion.
We tend to think that everyone is just functional and good and not self-destructive and that out of NOwhere we have some HORRIBLE SYMPTOM that needs to be "fixed"
Look at the whole picture. That is crucial in any patient interaction - in order to even know where to start - and to know how likely any change will be. NOBODY can 'help' by looking up a single symptom and reacting by trying to fix ONE thing (especially in a very complex and potentially very troubled personality)
Again, I could be totally wrong about this woman. She might have been a highly successful, well-balanced, healthy individual before this delusion. But that's not what my radar tells me.