User blog comment:Ari@n/yukino's sister/@comment-115.248.130.148-20131205204724/@comment-7418318-20131205205215

It's not impossible, but very unlikely. She doesn't look at all like the in Yukino's memories. Also Cobra said that the Nine Demon Gates are Demons from the book of Zeref, which most likely means that they were created as Demons, rather than converted into Demons like Doriarte and Minerva.

And her acting like the leader of the Nine Demon Gates makes it even less likely.