If she knew anything, Matty would have definitely blushed big time. He looked just fine - Knox didn't want to dress up and though she didn't really understand why, she accepted it and just kinda ran along with it, giving him silly looks every now and then.
She wouldn't have asked him to go by any means. In fact, maybe she even asked him to go to the greenhouse with her! Her voice was probably shaking and she was definitely blushing, but Taveon asked her to get to know him and that's what she intended to do.