By Michael Tedder The singer and mom-to-be is the richest female musician in the world. Rihanna is always on the mind of a certain segment of the internet, but after news broke yesterday that she is expecting a baby with the rapper A$AP Rocky, she’s back in the news in a big way. So with that in mind, it seems like the right time to look back on how the woman born Robyn Rihanna Fenty in Saint Michel, Barbados, became one of the wealthiest entertainers on the planet at the age of 33. How Much Is Rihanna Worth?Back in August, Rihanna’s net worth was estimated at $1.7 billion by Forbes, which mak…