You would best be advised by an Immigration officer. Per my knowledge; if your family has Qatar Res permit, they cannot be out of the country for more than 6 months, they would need to enter Qatar b4 6 months and then leave. In your case visit the immigration office and pay a fee and it could be all ok, unless rules have changed.
I would strongly advise checking with immigration office or your HR dept. Wish you all the best.