Gambling above one's income simply mean that they are borrowing money to gamble which is very bad because it's obvious they will use their next salary to settle the previous debt they owed so it's really a very bad habit, they might have even fallen into addiction because before someone starts gambling above his income it means that they spend so much time while gambling. Anyways it is difficult to advice people who have gotten into debt as a result from gambling above their income since they will always want to recover the borrowed amount they lost, the only thing you can advise them is to take it easy or go on an indefinite break, if they have entered into debts already they should convince the lender to be patient with them so that they can be paying it little by little till it is cleared then if they want to start gambling again you have to remind them of their past mistake and they should be responsible this time around.