Dear friend,
maximum extend for visit visa 6 months.if she pass 1 month she have 2 make medical check&finger print there is no more procedures the results will deliverd automaticelly to immegration then you have to
1- fill extension application form & sign it http://www.moi.gov.qa/site/english/forms/index.html

2-copy of her passport with Accompanying
3-copy of your passport & ID

then go 2 immegration

thats all