go ahead marry her and file the petition I-130 for her. National Visa center is processing for F2, married spouse and the children as below, just few month behind. It seems like the Visa number will be available once USCIS approves ( takes about 5 months) and sends the case to NVC,

NVC processing for F2A 08SEP13

http://travel.state.gov/content/visas/english/law-and-policy/bulletin/2014/visa-bulletin-for-may-2014.html

good luck.