No, aside from DH I would not tell a soul.
Most of my family are pretty privileged and I don't feel they need additional help, with the exception of my grandmother who I would just deposit extra money anonymously into her account periodically. Even though most of my family is privileged I know we would be asked to clear debts, etc, however I wouldn't be able to do that as most of their debts are due to silly reasons- like frequently updating their functioning cars because there is a newer model.
Aside from setting us up with a lovely house and so on, I would use the money to travel with WWF. The rest would be used for various causes as required, whether it's donated on cash, used to purchase supplies, or promote causes in need of awareness.