More specifically, a big fat alimony/child support check and possibly the income from a portfolio or income property that she got in her own divorce. Such women often don't have to earn a living any more than the housewife mom does, giving them plenty of time to "keep her company" while her unsuspecting husband is slaving away for their "future" -- which won't include him. By inducing a happily married woman to become discontented and to divorce, they seek to "justify" their own marital perfidy through consensus -- plus, they often can't stand to see a successful marriage when their own marriage/relationships failed so dismally.
I think you hit a key point right there.
It bears repeating.