I'd have to reset whiteACID's password, which would essentially block her from accessing her account, and then go in and do that. And I couldn't change it back the original password, because I wouldn't know what it was - unless I had access to her e-mail. She would've known. And I don't do that - it's a waste of time and privacy.
LET ME THROW U A MORE PLAUSIBLE SCENARIO...
Under the influence of a drug and/or substance, whiteACID or one of her many husbands that live on her premises, deleted said PMs. Upon entering sobriety, she was shocked to see them vanished and was quick to stir controversy - a talent unique to her, rivaled only by her ability to wed many men at once.