What Can I Possibly Do To Help An Abuse Victim?

Those who know someone who has been through trauma and abuse sometimes feel like they can't do anything to help, so they do nothing, they avoid and act coldly toward the person. What they can do that actually would be helpful is to understand that one of the things that can happen to a person is isolation. It can be because they are too overwhelmed, too fatigued, or too stressed to reach out to others, or they often don't realize time has gone by because of their fatigue; they may have ended up with fear of going outside or fear of other people (either fear of attack, fear of slander, or fear of having to deal with cold human cruelty and domination behaviors, anxiety about suppressing their own anger when yet another person acts disrespectfully or abusively),
or they may have actually been conditioned (brainwashed) to isolate themselves from others by a Controller/abuser.
Conditioning a target to disconnect from other people that they would normally be connected to is a very common abuser behavior that targets (no matter how intelligent or physically strong) are rarely aware of, and the effects can last for years, especially if no one around them understands the effects and trauma of manipulative abuse, whether it was from childhood or during adulthood, or both.
So if you think of yourself as a "compassionate person" and you're not suffering from the effects of trauma yourself, try reading up on what happens to strong, good, intelligent human beings when they go through trauma. You can do a lot of good in the world if you simply have a decent grasp on what happens, what people go through, what the effects are, and how to behave toward a person who has dealt with trauma (and how NOT to.)
That person could easily be you someday, and hopefully it won't, but if that day did come, you would find out how rare and how precious it is to find a person who actually grasps it at all, who treats you with respect, and who you can simply communicate with in a genuine way.