Qatar immigration rules dont allow RP for the parents or any other relation except for one wife and kids.The only other alternative is to get a property in her name here in Qatar and she gets a RP but this is not a viable options for every one. If she is below 60 can easily get visit visa extendable to 6 months and you can easily get it as many times as you want till she keeps on exiting the country after each arrival and re-enter on new visa. But if she croses the age of 60 things get difficult.