Holy moly! You totally did the right thing, and it sounds like the neighbor is totally aware that you were making sure she was safe. Single ladies gotta look out for each other.

It might even have given her a chance to calm down a bit to have someone break through her hysteria, even if it was the cops. And if the cops were that good with reassuring you, they were probably decent to her.

Poor woman. What she's dealing with sounds awful. I don't think a little gift would go amiss, though you don't have to due to guilt.