The joys of being a primary teacher

So, being a primary teacher has it's ups and downs.  Some days the children are reverent, and other days they just aren't, and other days, half of the children are reverent and the other half aren't.  Today was one of the latter.  I will admit, that when I first started teaching, we had a problem with reverence for the whole class, but over time it has improved quite a bit as everybody got used to the new teacher.  Now, however, there are two new children in class.  They haven't grown up going to primary, and actually the sister should be going to the older class, but she comes to mine.  I have the hardest time keeping her reverent.  Her not being reverent can rub off on at least some of the others in class.  I'm hoping that over time, she'll get used to things as well.  Class itself was not the greatest, but not the worst. 

But then, during sharing and and singing time, the two siblings were a handful.  The little boy just would not stay in his seat, and proceeded to inch himself across the primary room floor as the children heard a sharing time lesson about reverence.  Then, during singing time, the older sister kept talking and kept saying "I want to sing the vampire song.  vampire song.  vampire song..." over and over and over.  Someone told her we don't have a vampire song in the book.  Then she said, "How about the princess song?"  We told her there wasn't one of those either (although maybe we should have told her that "I am a Child of God" is a princess song).  Then, as we sang every single other song, she would sing "vampire song.  vampire song. vampire song." 

I'm hoping that as they continue to come to church, that the others will rub off on them, and they will learn how and why we are reverent from these other kids (rather than vice versa).  For some reason I tend to blame myself for their lack of reverence, but I probably shouldn't.  Any suggestions???