It is a matter of self-confidence and also trust in strangers. In some cases the trust is abused, in some not. It is extremely difficult to dance this dance of human encounter. The resonance between two people on an unconscious level plays, I think, an essential role. At all times, people had to consider whether or not they wanted to allow a stranger access to food and necessities. The inner intention, which is not openly spoken of in such moments, but which, when one listens into oneself, nevertheless comes across, is decisive for how one behaves towards one another. I think there is no general answer to the question of whether you should have let the woman in, but only an individual, momentary one.
Would you want to undo your decision?
I would not rule it out that I would let strangers live with me if I had enough space and money to afford it. I'd have to rely on my knowledge of human nature. However, it is unavoidable that you are still wrong or that things happen that you have not taken into account. Life is always a risk, where you have good and bad experiences. However, I think that people generally respond positively to encouragement and to their good potential. A deeply suspicious person should not let strangers live with him.
If it were normal to have a pot of food ready for beggars or travellers, one would have developed a habit in it. I assume, for example, that in seven out of ten cases trust would be justified and in the other three cases someone is acting ethically wrong. Since we no longer cultivate such a culture, there is no established habit in it. That's sad in a way. ...