If she is above 60 yrs, then it will be difficult as Qatar has a policy of not allowing visas for relatives above 60!

Otherwise, go to www.moi.gov.qa, in the MOI forms, fill up the tourist visa and submit it to the Airport visa section along with your pp copy and mother's pp copy. It costs QR200/- or so. She will get a 1 month visa.

2. If she wants a 6 month visa, then go to any typing centre fill up the form and go to Mesaimeer immigration or Gharafa immigration office and get a visa for 1 month which can be extended for 6 months. within one month of arrival she should go for medical in this case. The visa costs QR200/month..