Is gambling OK? Don't bet it! There's not an easy or instantly obvious proof text answer to that question.
Of course, it's not a sin if you do not take money from the family and do not deprive your child of simple things. After all, your conscience must definitely wake up, and so there is extra waste, personally your business.
The outcome will determine if you are making a sin or not, if you are just spending what you can afford and you do gambling for fun
then for sure you are not making any sin here, you consider only gambling for fun and that is necessary to avoid problem in the future.