So here's the thing: there are very few medications that you have to take everyday to save your life. In general, if you need to take medications everyday to save your life, you're probably hospitalized -- because you have a medical condition that requires constant or frequent monitoring. So what was Nancy taking? I suspect it was a blood thinner to prevent a stroke (because of an underlying arrhythmia, which is common with age), or a medication that controls your heart rate. Every dose does not automatically = life saving. You can miss doses -- many people do.
So the theory that she is not alive because she is frail or missing medications doesn't make sense. The blood splatter in her front entrance also doesn't make sense: if she suffered a blunt injury, why was there so much blood splatter, even if she was on a blood thinner? If you're walking at a constant or near-constant pace, or carried at a constant or near-constant pace, blood splatter doesn't look like that -- it drops in a linear pattern, even if you have a nose bleed.
My theory is that she fell sometime during this episode, maybe hit her head, and suffered a subdural hematoma while she was on a blood thinner. This is a very common condition in older people who fall, especially while on a blood thinner. Are there any chipped or cracked floor tiles in her home? Did she have a cane or walker that is lying on the floor where she might have fallen? She could have suffered a nosebleed in the same fall and head trauma. Then someone carried her out. They struggled, paused, and shifted her weight, which explains the blood splatter in the front entrance. Subdural hematomas can cause loss of consciousness, and the symptoms last for days or a week -- who knows what happened from there.