If a woman doesn't know that her husband is gambling, then it's already a marriage full of lies. It means she doesn't know her husband and doesn't know what he's doing.
A married friend of mine had to sell his luxury car because of gambling. When he sold the car, his wife found out he was gambling, and now they constantly fight.
On the other hand, has this woman ever asked where husband spends money on? Or has she ever told him that it bothers her how he spends money? I did not tell my wife that I went for lunch with colleagues and we ate so much tasty food, that I had to tell her I wasnt hungry when she asked me about dinner. Does it makes me a liar? Nevertheless, I wont agree that gambling has any connection to divorce rate. If second half never raise any interest to what other half is doing and spending money on, there is no right to blame only one person if situation is getting to divorce.