To my knowledge it can be done after the expiry of the 6month limit and not before as the system has fixed re-entry date of 6 months; there is no need to re-apply again for the visa. You have to wait till then (6-9-2013) and there is a formal fees to be paid if she is in her husbands sponsorship. If she is on company visa then I think it is to re-apply.
By the way qatar has the dirtiest of mandoobs in entire GCC (off-course the complete administrative system is a mess)and he will not answer your calls till the end of ramadan holidays. Try to speak to him later as there is still enough time left. OR go to his office and catch him right there.