The stars of ‘Seeking Sister Wife’ and other black polygamists on the realities of dating while married — In many ways, the Snowdens are a typical 2019 American family: They have a lovely home in the suburbs and three beautiful children. They’re spiritual, but not religious, well-traveled, and very much in love. Ashley’s a mom-preneur who homeschools their children while consulting with clients about healthy lifestyles and trying…