I like this one. It is kinda of a wierd thing to say. But at least she will laugh.
As the door closes and it becomes silent for a second you say something like this.
''Now you probably wonder why we have gathered in here'' ( of course will full confidence)
She will probably laugh about it, perhaps little embarrased but it allows you to take control over the conversation
Or, she will ask you why, and its game on!