I found a paper with a similar structure, method, and conclusions from an attendee of a conference I presented at. Is this plagiarism?
(I agree with the comment from UJM.)
Since she was &quot;curating&quot; the journal, I guess that means it was a special issue, and there are other, permanent editors. You can approach them. I think if you do this carefully, there is not a great risk. What I mean by that is to focus on yourself: you have concerns that your paper is damaged by this. Don't speculate on her process or motivation.
If you are a student, obviously discuss it with your supervisor first.