In an interview with Den of Geek, director Bryan Singer said that no one should expect to see the Scarlet Witch in X-Men: Days of Future Past.
When asked if the Witch was in the film, Singer responded by saying, “There may be a reference, but no, no. There are 26 main characters, and with seven of them, there were a lot of restrictions in terms of schedules.”
In fact, it seems like the Scarlet Witch’s brother, Quicksilver, doesn’t even have too large of a role in the film. Singer said, “He was in our script quite early. It's not a big part in the script, he's not there throughout the picture. Super speed's been played throughout the series - Twilight uses it...I had some ideas of how to do the power, the speed, that I hadn't seen before. So I started development with super high-speed photography and stuff like that, so yeah. It's a fun character.”
So I guess it turns out the little girl in the photo with Quicksilver is a homage at best.
In X-Men: Days of Future Past, the ultimate X-Men ensemble fights a war for the survival of the species across two time periods in X-Men: Days of Future Past. The characters from the original X-Men film trilogy join forces with their younger selves from X-Men: First Class in an epic battle that must change the past - to save our future.
X-Men: Days of Future Past comes to theaters May 23, 2014.