From what I understand, according to Qatar Labour Law, your wife has to be employed by a company for one full year before being able to avail of Maternity leave. As for Paternity leave, I'm pretty sure that concept is unheard of here.

Maternity leave is usually 50 working days, and can be taken before and/or after delivery. I don't think there is a specification for how much can be taken before or after, it all depends on your supervisor's approval.

I suggest you speak to the HR dept of your soon-to-be company and sort these details out.