Curious why she was not buried with husband where he is in another cemetery and why he was not listed on her death certificate.  If that is a Catholic cemetery, perhaps they didn't allow it if he were of another faith. My grandparents were buried different places for that reasons. Perhaps she was divorced or perhaps the person filling out the information just didn't know who her husband was. Does it say who the informant was on the DC? They might give you a clue. If you have any luck getting hospital records, let me know how. I think that is doubtful.