Lucy and the twins certainly noticed how Zelda suddenly went back to being that clueless ditz that they remembered her being, but had yet to connect it with the necklace they had just removed from her.
"Put that around your neck," Lucy ordered Beth. "I don't want someone to steal it again, until we return it to its owner." Her cousin did as she said.
Suddenly, she felt confused. She looked around like she didn't know where she was. Then she looked down at herself in complete shock.
"Beth?" Lucy asked. "Is there a problem?"
She looked up. "Beth? What the hell are you talking about?" Then she looked back down at herself in disbelief. "I'm ... I'm a girl."
"Well, of course you're a girl," Lucy said.
"I'm supposed to be a guy!" Beth yelled. But at the moment, she didn't go by the name Beth. She went by the name Biff. Biff Meadows.