There is nothing wrong gambling with big amount of money as long as it won't affect you if it doesn't work as plan or if you lost, there are people who actually gamble with what they can't afford to loss properly to win big as you said, winning in gambling is never certain it is practically a game of luck and shouldn't be gamble with money for family up keep in other no get your depressed after lost because you choose to gamble with what you can't let go.
Most people can not think like that. With a big amount to play gambling, they imagine winning big because they can place a big bet at once. But the reality will not be the same as they want. They need to use the money they can afford.
Winning in gambling is uncertain so you don't have to chase the win. If you can treat gambling, you will not risk too much because you understand the losses.
If you are aware that money is for your family, you will not risk too much and will not use that money to gamble before you allocate the money to your family.