She's really missing the point. The problem wasn't that she believed Eve, I'm sure she's aware of that. She's deliberately avoiding taking any accountability for her actions.
She made her mind up there was going to be a problem before Charlie/Eve walked in the room. As she did with Lacey previously. It's how she horribly accused Charlie, knowing she hadn't given her the time of day to state her case. The fixing of Charlie's hair before she vocally became nasty just made it all worse. How she handled the information given to her by Eve is what makes her wrong. None of the rest of them behaved like that, when I'm sure they also believed Eve.
She's shown who she is.
And Polly seemed raging that Eve and Charlie walked in together and made it her purpose to stir things. Focus on your own sh1t relationship piggy!