Britney Spears is planning to be with her sister, Jamie Lynn Spears, when lil’ sis gives birth… any day now.

According to E! News sources, Britney Spears and dad Jamie will be on a plane to Mississippi as soon as Jamie Lynn Spears shows signs that the baby is on the way.

According to the source, “Jamie and Britney are standing by to get a call and when they do, they are jumping on private jet.”