I wouldn’t tell a soul. As much as I would love to help my family, and I would, they would get more modest amounts than if they knew. I would set up some sort of business in name only and pretend that I was making money through it, and help them that way. I would get lawyers and financial advisers on baord to make it all look legit. Alternatively, I would look to get a better job and help them slowly this way. Just extra money that could help with a deposit/extra money every month to make sure that they’re not stressed about finances.
I would buy a property that I wouldn’t move into yet. I would continue renting for the next few years, until I could justify the move based on other earnings from my job or said business.
I would get plenty of legal and financial advice all the way. In a few years, I would help one of my colleagues retire. But she would have to sign an NDA. She doesn’t know friends or family, so wouldn’t get round anyway.
If I get married, I would make sure that legally only some of that money ever becomes marital assets. So in the case of a divorce, most of it would be protected.
Good luck to everyone playing. If you win, get the right advice and do use the money for good.