miley-liam-family-230.jpgMiley Cyrus and Liam Hemsworth announced their engagement just last month, but apparently she's already got babies on the brain!

A source close to the 19-year-old starlet and her 22-year-old fiance tell Us Weekly, "Miley and Liam really want to have a baby quickly," adding that Hemsworth is the one pushing for it after his older brother Chris and wife Elsa Pataky welcomed daughter India Rose in May.

So what about the fact that they were both babies just two decades ago? "They are both mature and ready for this," says the insider. "Miley is 19 going on 40."

Do you think Miley is ready to have kids?