If you mean the the Queen of England - she only has a net worth of about $450 million (at best). The "Crown" has about $10 billion in assets, but it belongs to the UK (not the Queen), and any of it that is sold would simply go directly to the Government Treasury. And it's not enough to end world hunger in any case.
You have commented that you are talking about Queen of England. Her worth is $450 million, and while she does own many things they are also considered part of her country's heritage. And no one can stop world hunger tomorrow. Much of the aid that is sent to areas has been high jacked by warlords. You seem to have a very uncomplicated view of the world.