Interview Dilemma

[SamMont]

I went to the NVC website under the interview preparation and it says we need to bring a marriage certificate to the interview, however in my city (Houston) i read that in order to receive a marriage license we both need to bring out social security number
How can i bring my fiance's when she's still applying to be a citizen?
What can i do to get the marriage license for the Interview when my city has a this regulation?