I have few questions for you. First, is it the only way you know to earn more? Are you willing to put the money that you have at risk? What if you lose? Do you have other options? If you could answer all questions with yes then you could it's just fine to gamble your wedding funds.
If I will be in your situation, I won't put that 0.04 Btc at risk but I would rather find ways to earn just to sustain my wedding expenses.