Bill crossed his arms, shrugging a little bit. He wasn't entire sure what the situation was, just that Percy had told her all about his plan. Its not like all of the people helping him were being terribly secretive with their public comments.
"I don't know. Percy, well, he certainly isn't a good liar, so maybe he just told her. But he had to know that there was a reason she didn't know." Bill said, he trusted Percy not to right out tell his secrets, but he knew that Percy wasn't as good at lying as the other Weasley children.