Wonder Woman Annual - just a random girl in Brazil on a beach. Not Yara. To suggest it's Yara's 1st appearance is bizarre that's like saying "there are no girls in brazil other than Yara. It's a country devoid of human life"
Death Metal 7 - It's a one panel picture of Yara in which she is unnamed. Had the solicits for Future State not been out we wouldn't know who it was. NOt a 1st app.
DC Future State Preview: no comics contained therein, but plenty of pictures of Yara, and she's on the cover. However, I think this is considered a preview and not a 1st app (sort of like the Darkhawk Marvel Age controversy)
Which to my money leaves Future State WW as her first apperance without question.