Good Samaritan?

I went to the mall this week and as I was getting out of the car this lady was trying to flag me down from across the row. She was much taller than me and I am 5’8” and just a sturdy looking gal, at first I was going to pretend I didn’t hear her and keep walking but she was persistent. As she was walking up to me she told me her name was Caitlin which isn’t common for someone who seems to be in their 40’s, but what ever and she was telling me that she was so so embarrassed to ask but she really need help and seemed a little frazzled. She said she needed like 4 dollars because she ran out of gas she had to take her daughter to the mall and she was trying to get back to work, and she kept saying she was “so embarrassed” to have to ask, and she would mail it back to me and kept rambling. I was still feeling nervous- I mean I would love to help someone but I was by myself, and because of my back I was not feeling real strong on my feet at the moment if I needed to be. I just kept holding my purse closer as she approached, and I did unzip it to start to look because for most of the week I did have a couple of dollars just hanging out in there, still nervous, I remembered that I had spent my last dollar on a bag of Honey BBQ Fritos that my stomach had been regretting all afternoon. So I stopped looking and told her I was sorry and I didn’t have any cash I spent my last dollar on a bag of chips that I regretted buying. She was ok with that answer and walked on across to the bus stop?
That is seriously one of the oldest tricks in the book, it could be legitimate and I feel bad if was, but how do I know it was legitimate and I wasn’t really up for any funny business.
And really almost everyone has credit cards anymore, so couldn’t she have used a credit card? Well, if she really did indeed need some help I hope she found it. I guess I wasn’t a good Samaritan this week.