The Syrian consulate has changed so had to try to get proper details out of them. I talked with a lady there who was a little reluctant to stated the required documents, but she says all she needs is her passport but I am not sure they are telling me full details as a non national. She say you both must report with your passports to apply between 10:00 and noon. So best your fiancee phone and talk in their native tongue and as a national to the real requirements direct by phone. The new number is (66) 2 168 7777
I need you to have your fiancee to confirm this as I worry about its accuracy. As some times embassies do not tell non nationals alll the full details
Hope that helps.