Gambling addiction is not just about money, it brings down trust and peace at home. When it gets to the point where someone can steal from their children savings or pile up hidden debts, it shows how far gone they are. At that stage, willpower alone can not  fix it, what usually helps is strict measures like cutting off easy access to cash or probably getting professional counseling.. 
Families also have to be firm and supportive, because too much shame only pushes the person deeper into hiding. Relapse can happen along the way, but with the right support and effort, it is still possible to recover.