Visa on arrival at Salwa border Qatar

Hello folks,

My sister and her kids(canadian citizens) are currently here on a visit visa. She has been here since Nov 5, and so her 6 month visa will end in May, however, due to some reasons she does not wish to return to Canada till after Ramdan(August).

I"ve heard visit visa can be extended for another month or so? But i dont think it will be extended for 3 months, correct me if i am wrong.

Anyway, the only way i cant think of is that she exits Qatar and returns on a  visa on arrival which is easily extendable for 3 months. I was thinkig that instead of buying a ticket and flying to another country, is it possible that we just drive to salwa border, exit the qatar border, and then return from no mans land. Notice that i said return from no mans land, that means we will not enter Saudi, but  merely exit qatar border and re enter qatar border at the same time.

Has anyone else tried doing this? Also, just to be sure visa on arrival is available on the land border too yeah?

Any other suggestions to deal with the situation are welcome.

Thank you!