I have verified that the user is a member of jira-users (I suppose she would be unable to login otherwise). The "Delete Own Attachments" permission is on for Jira Users. In addition, I have verified via the Permission helper that she should very well have this ability in general, and for the specific issue. I also verified that the user in question did in fact attach the files in question. The issue is not closed. It is In Progress. When she hovers over the attachments inside the issue, the trash can does not appear. When I perform this as Administrator, I am able to delete the attachments.