This is before I've had my caffeine, so I can't guarantee the credibility of this suggestion. 

But what is up with the laughter and comment from Mbl when the kids are being called downstairs? Typical teenage angst? An aborted conclusion to the teenagers' conspiracy? 

I was originally thinking that Mbl just told the teens about what she saw between Nat and Alpha. But Nargle's reaction doesn't seem to jive with that, unless, as the youngest, she feels too squeamish hearing such discussion. It's a shame we really didn't get much context for her statement.

Anyway, my morning, pre-tea, thoughts. Use them as you will.