are you sure qatar airways still doing the visa? i brought my mom last year or i think a year before, when I came to their office they said they dont do it anymore and asked me to go down to the visa office next door to the airport.

I went to the one in the airport, was hassle free. Once I submitted the necessary papers , I can check the visa application progression on line. Then once it approved my mom just print it out from my home country and she carry that to show in the immigration.