If she have valid RP and not outside Qatar more than 1year, she can come back to Qatar
but
After 6 months (residing out of Qatar) she has to take RETURN VISA.
You just go to service department with photo copy of her RP and Passport. Request for Return visa (sometimes authorise person ask for written application, take help of typist outside service center) . Return visa fee is 500 QAR.
Note: Return Visa valid for 15 days to 30 days only.
Mean, 1st confirm arrival date of your wife than proceed for Return Visa.
I had done same for my daughter before blockade.