I have done exactly the same. Woman walking down a road, obviously upset - no pavement and a very busy dual carriageway, so I guessed she had got out of a car. It was evening, she was wearing a tiny dress and carrying her bag. I asked my partner to pull into the next lay-by and I walked back to her, telling him to stay in the car in case two people walking up to her scared her. I talked to her and she said her boyfriend had told her to get out of the car, so she did. I explained that my partner was in our car and we would take her anywhere she wanted to go. We dropped her off where she wanted to be, I asked if she needed anything else and she said she would be fine. I wondered the same as you - how much more should I do/have done? Have to say, not sure I'd do the same thing again: I just remember seeing her and feeling I had to stop and help, but I wouldn't necessarily say it was a smart move or that everyone should do the same in that situation.