We made sure she knew all of my biographical information (parents, siblings and address, names, work, etc.). This really helped because it seemed like some of the embassy staff who conducted initial screening (before she had her formal interview with the consular officer) were asking questions like what is his address. Some applicants who did not know the answers to multiple questions were advised to return when they were more prepared. Looking into their eyes and smiling when you answer helps so they know you're confident.
She also brought pictures showing us together. She attended the interview by herself because I was unable to attend. Also: be early! She went there to wait in line super early...even though she had an appointment time. This helped because she was not the only one with an ~8AM appointment time. Once she was allowed inside, she was out of there by ~0930.
Also: don't bring cell phones or perfume (best to bring just papers and pictures)