Well I'm not from the South but the Midwest and nicknames were all over here. i didn't have one but had a cousin "duckie", my brother was "shorty",went to school with a "cookie", "cricket",and "peaches". My dad always called the babies in the family "peanut". That nickname only lasted till the next baby came along.
it was also common to call adults "aunt" or "uncle" whether they were related to you or not. Even my dad called our elderly neighbors "grandma and grandpa" as long as thye lived. It was considered a sign of respect.