The Buddha once said something similar to this in the scriptures, "If you try to figure out the Law of Kamma, you will go insane. e.g. Civilians killed in a war - we say: "Why? Why should they be killed in a war?"
Some woman becomes a prostitute because she thinks that's the best way to feed her family. Why? That might have a different reasoning behind it than a person killed in war. But a lot of people who are in areas that have a war going on, sometimes I wonder to myself, "Why do a lot of those people stay where they are? Why don't they get out?"
For every Israeli that comes here, and who tells me they don't like living in Israel, I have exactly the same thing to tell them, as I tell somebody from New York city who tells me they don't like living in New York city, "Get out, there's no need to be there". They actually have a choice.
Some people in a war area don't have any choice, that's one thing, but some people do have a choice - to stay or not stay - particularly as a civilian.
So if we have a choice to stay in an area where it's very dangerous, or to leave it, and then later we are killed because we stayed, then that's actually our Kamma. We made that decision to stay.
Now if we didn't have any choice, and we just get killed because we live in an area where there's a war, Buddhism will say it's our "past Kamma" which causes that. We can't answer that, as to this life.
The theory from Buddhism is something you can take if you want; or not if you don't want to that some things come from past lives.
Why are we born healthy? Why are some people not born healthy?
Why do I have my eyesight? Why do some other people not have their eyesight?
Those are pretty big, heavy, Kammic things that Buddhism will say depend on past lives. It's not something we can answer.
I know, recently, a story about and Australian fellow killed in Iraq. Why was he there? He was with a business there that was making money out of rebuilding things. He was getting a big, fat salary, that he thought that if he went there he'd make lots of money, and he didn't respect the dangerous conditions that he later got killed in. I think I'd rather take less money and work in Sydney instead. So that was an immediate cause and result, in the sense that he chose to go into a war area, when he wasn't even a soldier.
The other part of the question: "A woman who sells her body, because she must feed her children." I don't agree with that at all, because it's their own wish to do so. They may be pressured in to it, but that's a bigger question that goes way beyond the scope of what we're doing here.
Prostitution, as probably all of you know, is what they say possibly the "oldest profession on the planet", and the psychological aspects that go into why a woman does it are quite vast and multiple.