How come nobody has asked if maybe Natalie made the pinky swear. 
Because Will made it a point, after Natalie entered the house, of verifying which of them had which conversations with him at different times.
Of all the people in the house, it is Will who would have a grasp on which twin did what at which time before Natalie was brought in.
As for Adria: Her comment about the Lord showing her who to nominate was blatant.
As for alliances, she was in an alliance with Will, not with Karen or Drew. Drew and Cowboy were the logical ones to nominate, but Adria showed her colors and stabbed Will in the back.
As for the mastermind behind girl power, you're overlooking the real talent: Jennifer/Nakomis. She was the mastermind behind the plot to evict Jase. It was her plan, incorrectly attributed to Will at some point on the Canoe site, but cleared up on a telecast after Jase was thrown out.
Diane is a lowlife skunk. Why Adria listened to her about evicting Will floors me...but Diane's motive may have been that she didn't like feeling threatened by Will...and that threat was Drew's friendship with Will, which I think threatened Diane's womanhood.
I don't know whether to believe her change of heart now or not...but I think Drew voting for Will was his way of appeasing any suspicion she might have had. Everyone thinks Drew is mindless and whipped...and I think Diane worried that Drew might be manipulated by Will in some way she couldn't counteract.
Mind you, it's just a theory I've concocted. But I stand by my assertion that Adria violated her alliance with Will and that she was bigoted in her nominations of Will and Marvin.
It all boils down to "gut" -- mine tells me one thing, and yours tells you another. We may both be wrong...or not...