They are more desperate, may are insecure (because of that failure). I know one who managed to get married quite fast after her first divorce to a very solid man, but she was still about 25, good looking and from a rich family. Most other cases are quite sad to begin with. Plenty of my friends are dating single moms, they are mostly divorced too already or just not exactly the largest fishes in the pool (not the richest, best looking, etc..), some have various addictions, and single moms are good at being tolerant to that stuff.
There's no way I'd take these females seriously given the fact that I'm decent looking, have money and not much issues in my life. Plenty of young and eager girls out there, why bother. If she would still be young, VERY hot and I'd like her for many reasons, I could consider it, but then it should be a girl that she has, not a boy. I could not stand a boy from a different man, girl, somewhy, would be ok.