cussing at children

We were running errands. Divide and conquer is our strategy. Brian and Elliot went to Trader Joe's while I took the older three to Carter's. As we were crossing the street to get to the store, an older woman dropped her change purse in the street while crossing in the opposite direction. There was a car approaching, so I knew the right thing to do would be help her pick up her scattered change. I called to her and said we would help her and I thought I heard her grumble about something, but I assumed she was mad and frustrated that she had dropped her money. So, quickly, I told my boys to run and help her pick it up.
MISTAKE.
They, being the sweet boys that they are, did as I asked. Oliver was bent over in seconds to help and the woman almost stepped on his hands!! She stomped on her money to prevent them from helping and then said, "Go to Hell!" My jaw dropped. I thought perhaps that she thought they were going to steal her money or something. I said, "They're not going to take it, they are trying to help." She repeated, "Go to Hell. Blah, blah, blah, negative something about war, or violence... Go to Hell." I was shocked.
Completely shocked.
I called them back (this was a matter of seconds.) They were in my arms, safely, and I heard her say it AGAIN. I told them let's go... and turned and said loudly, "You need to watch your language." And of course that merited another wish of damnation.
I made sure to keep talking loudly to the kids as we walked away so that they wouldn't hear anymore from her. What a poor deranged soul! To curse at children?!

The kids were in slight shock in the store. I think they were scared that she might come in. They kept asking me, "Why did she say that? What does 'go to hell' mean? She almost stepped on my hand!"
I told them that she was mentally sick~ that any normal adult does not cuss at children who are trying to help them. And I told them that Hell means without God. Oliver replied, "So she wants us to be in hell and I bet she wants to be with God." (hmmm~ not sure about that one.)
I'm afraid they won't forget this encounter. All throughout the store, we chatted about mental illness, life after death, how to respond to hateful actions, and why we shouldn't say, "Go to hell."
I'm sure the others in there were wondering. And I realized that I literally would have even physically fought this woman if needed to protect my kids. Unfortunately, my hunch is that she is the one who should have been protected years ago.