Well I wouldn't necessarily say it is fake. Although, I have not seen Hansel and Gretel I did google her to see if she does wear a cloak, and she doesn't she wears a feathered black dress. The reason I say it could be real is for various reasons first being that the x_men_series IG page got low quality fake looking pictures of quicksilver months before an actual photo of him was released by an anonymous user, which turned out to really be him. http://instagram.com/p/c7LXIvM9z9/ http://instagram.com/p/c7N56wM94a/
The second reason reason is, Hugh Jackman, while filming was really excited about an X-men reunion on set that he tweeted about, but that if he said more he could get in trouble and told fans to get it out of Bryan Singer. I cannot find that tweet anymore either, which is weird because if it was just a reunion on set why delete the tweet. Third, she also denied she was in Wolverine and kept doing so even after people saw her in the trailer, so her comments on not being asked back could be false. Reason number four, was when Bryan was asked about Jean and Cyclops being in the movie to which he replied "who wouldn't want to see them". Reason number 5 is James Marsden was seen returning from Montreal on the same plane as Halle. The photo could be fake, but all signs point to a yes on seeing Jean and Cyclops whether they are young or not; I don't know.