Working with kids...input please!?

So I have just started helping my aunt teach a 5th grade religious ed cl. She has had this cl for a while and the first day I went, I was amazed how misbehaved they were. ( My aunt is one of those people who think they know everthing.) Her cl is out of control. There are about 14 kids and most are very quiet but there are about 4 who are so misbehaved. The cannot sit still and answer the question..."What is faith" with the response"Video games, or cake" or something stupid like that. I want he to know that the cl should not be able to act this way. How do I bring it to her attention? How do I help? I don't want to hurt her feelings