Fio: I can't help wondering how the children of these women feel about answering the question “What does YOUR mummy do for a living?”
Do you honestly believe they have some sense of moral dignity and decency? On any given day I'd reckon at least 50% of Thais are living off the earnings sent home from some female family member. They don't care where the money comes from or how it's earned just as long as it keeps on rolling in.
And don't fall into the trap in thinking they're driven in to it from poverty & starvation, those northern Thai families with all their daughters on the game have "big face" with their wide screen TVs and DVDs, and 2 door fridges.