Not just his cousin but:
The age that a female can marry with parental consent and/or judicial consent in Mississippi is 15 but at the time was 12 (as per the UK Civil law which was adopted by most states after the revolution. It's still 12 in Massachusetts and 13 in New Hampshire - most are now 15 or 16 [as in Canada] - strangely, unlike Canada, states frequently distinguish between males and females allowing females to marry at a younger age.)
Wait! It gets better:
A fabulous performer though. The song starts at 1:10.