http://www.ijssh.org/papers/87-CH014.pdf
written by a Thai woman.
It appears that just about anyone who would marry a Thai woman who was divorced, widowed, or who was a single mother would be doing her a big favor just by marrying her.
And, Englishmen tend to prefer women with at least a bit of sexual experience (compared to their Asian counterparts, who largely prefer virgins, or who might only consider marrying a virgin).
So, the markets clear, and everyone is happy.
...widows and divorcees in Thai society are looked down as used or unwanted objects. Marrying a Farang is not only a good opportunity for these Thai women to live in a society with higher living standard but also an opportunity for them to feel the value of their bodies...