In Resident Evil Revelations 2, the main antagonist is known as "The Overseer". When examined closely, it becomes apparent that the Overseer shares many characteristics that Alex Wesker may have. This leads me to the conclusion that Alex is the Overseer. I will explain my reasoning in the following paragraphs. By the way, this is similar to my old theory, I reposted not because of your hate, but because I had considered Alex's role. XD. Seriously, you all are so impudent... Except for Tridenter -- he's cool.
The supposed look of the Overseer raises much speculation about who this taunting fem may be; note the following features of the Overseer: she has light, long, and blonde hair, she is a caucasian female, and she is noted for wearing white clothing.
Let's put this into perspective, Alex, is, of course, part of the Wesker family. In which, is noted for having blonde hair and have shown signs of a dominate Caucasian background in the family. These attributes directly point towards Alex.
Additionally, the whereabouts of Alex before this game, (assuming she is in fact the antagonist), are unknown; and her being accounted for in this game gives us more of a history on her, so-to-speak.
So yeah, this is just theory I have. Thanks for reading!