Here's a Google document which lists all of Emma Frost’s appearances in the comics. The appearances are categorized by type; major, minor or background (bg).
Also includes various notes about the appearance for each issue.
 
Open by selecting one of the versions below.

1. Web page version
2. List view version
3. Spreadsheet version

• Q: Why not simply use Comicvine to get the list of appearances?
• A: Comicvine appearances are not qualifed, so issues where Emma has a major role are not easy to tell apart from issues where she only a appears in a panel or two.