Women selling trinkets in Ixtapa

Whenever we go out to eat in Ixtapa there are always women and young children walking amoung the tables trying to sell little toys ect. I recognised some of these women from previous years and they all seem to have infants or small children with them
Who are these people and where do they come from? I don’t see them in the day. Are they just trying to make a living or is this some sort of a scam. They are always polite and the children are very well behaved. What’s the story behind them?