Actually, her doctor told her two kids ago to stop having kids. The last one they had is very ill and is still on oxygen, or was the time of the announcement of the latest Duggar. I think these people have some sort of underlying pathology. Just because they have money and no debt does not negate that possibility.
In fact, per Dr. Drew, they may have some sort of post-miscarriage syndrome. Their very first pregnancy ended in miscarriage and I guess there is some sort of snydrome that people can go through after that that causes them to breed continuously. It was news to me but if Dr. Drew says it, it has to be right... right?