Wonder it they extend 1 months visit visa. Any way could check with any imigration office. Insha Allah, if they do allow, you need to follow the below process.
You need to go to the main imigration office in Gharafa. You need to carry
1) original passports
2) copies of passports ( urs + wife & urs+ daughter)along with your RP copy.
3) passport size photograps (2)
4) ur debit or credit card with a balance of atleast 400 riyals (200 X 2)
Once there, you need to get a form typed from the people sitting outside. They will help you to attach the documents in order. Go to bldg no 4, take a token, and submit as ur turn comes.
Generaly the visa is ready within three working days.If u r lucky the vey next day . You can get the details from www.moi.gov.qa website