My sister's adopted baby

My older sister was 23 when we discovered she wasn't going to be able to have a child. When she was fifteen her first boyfriend had given her an STD which made her sterile. So her husband looked into adoption, and one day they brought home a small baby they adopted from Tennessee. It was exciting, and a little strange, to see my sister holding a baby in her arms who wasn't even hers, but I could see the joy it brought her and her husband. No one ever said much about the fact that the baby was white. (yeah we're black)