I don't think it's quite how you word it or possibly she worded it. Women don't feel stuck in relationships that aren't working due to financial obligation quite as much. It doesn't happen more often when their partner is poor, it's just when they're in jobs and social circles with capable, available men and no financial restriction to force them to stay, just like many men, they will look or test the waters when they feel neglected, unwanted or misunderstood. I think they may have always quietly cheated, sadly, no matter how much the man made. And today's fast communication, impatient society is making it harder for people to see that things can work themselves out if they keep trying longer than they think they should.