Uh, she definitely worked hard. She's an actual "self made" billionaire. She did it through constantly working in media over decades. Do you think anyone said "let's just give this young black woman a billion dollars?" She was literally the first black woman to have a billion dollars, so no.
Her weight has always been an issue, so this is only news to her most rabid fans.
No, she wasn't. Unless you are double counting her husband's money. She was married to the founder of BET. If you think they each did equal work for that, the money would be divided evenly.
When they divorced they had less than a billion each. And their collective wealth only passed $1 billion a few years before Oprah did it on her own. Saying "they were both billionaires" seems wrong.
If you and your spouse have $1000 total, how much money do you have? The answer is: you have $300 and your spouse has $700 because there's something amazing that you have to get for the house.
It's not self made if she worked her way up. First she had to get a job. Then she had to have someone see something in her to move her up. Then someone had to talk good about her to someone else. Then through the power of networking, she made it to where she is. A lot of success in the entertainment industry is either landing the role that will get you set for life(think Daniel Radcliffe as Harry Potter), or getting to know people who know people. And for a lot of people, that means other people are helping lift you up.