It sounds as if the perpetrators knew of the victim, watched her and knew what they wanted.
The men had busted into her home and roughed her up; they demanded money and prescription drugs.Here is someone living alone in a lightly populated area. Since she is described as disabled, one would assume a certain amount of physical weakness and vulnerability. She's probably living on a few hundred dollars a month, and she has been robbed of more than $1000.
These thugs need to be hunted down, but it is unlikely they will be caught -- at least not for this particular crime. They will do it again.
I don't know if this woman had a firearm in the house, though a gun will do no good if a person does not have time to access it. Did she have her doors locked? Were they dead-bolted? Any door can be breached, but home invaders should be forced to make a lot of noise.
Most everyone has a cell phone these days. Is it quickly accessible? Does it have 911 on speed or voice dial?
Never open the door to someone unknown and unexpected. Storm doors can be beneficial. They won't stop a bullet, but neither will most exterior doors. They will provide a second or two to shoot the bolt and run.
I don't like indoor animals, but, in a situation like this woman's, I would overcome my prejudice and have a dog in house. Security alarms would be another option.
It's really sad that we have to protect ourselves against these kinds of threats. Home invasions in rural areas certainly aren't a brand-new phenomenon. The events portrayed in In Cold Blood, just to pick one, happened in 1959 out in the boonies of southwest Kansas. Still, they do seem to be on the rise, and, while we should not live in fear, we are wise to be aware of the potential.