User blog comment:Gunman6/Alternate and Potential Storyline for ''24''/@comment-4864110-20141104063239/@comment-5064943-20141104155359

Yup, it's true that there's no mention of Nina's family relations whatsoever so it's definitely safe to assume that she was either an orphan or that both her parents passed away long ago.

The evil twin concept was just something I thought about awhile ago and the show tends to always conjure up hokey material despite no previous mention of any previous events leading up to such.

We probably don't get more than one more season but I can always dream ;)