Ken,
The embassy only contacts the visa applicant and the petitioner is not normally required to attend the interview. All the required documents, including those from you, should be listed in her interview instructions.
Bring an original I-134 Affidavit of Support notarized by a U.S. notary and your financial documents (Tax returns (3), W-2’s, employer letter, etc.). This stuff is required.
Also bring the originals for any documents that were filed as photocopies with your petition. Be sure to include a complete copy of any divorce decrees.
You should also have evidence of meeting within 2 years before filing and evidence of a valid relationship, including phone records, some sample letters (6-10), photos, etc.
Ray