I didn't know jesus had a sister, but contemporary accounts by josephus et al. indicate jesus existed.  if he had a sister and their dad was a carpenter, that wouldn't actually be a prominent occupation AFAIK.  maybe it was in those days.   nowadays around here most of the carpenters are immigrants from mexico because it pays so poorly.  they get hassled by "la migra" and the cops all the time.  maybe jesus, his sister and their dad were living in the same conditions.