What we see or feel is not always what we say.
Most of us are intelligent enough not to speak when you know what you are going to say will adversely affect those around you. Rona seemed to be lacking this bit of intelligence.
The others were frightened, that's understandable. Their fear didn't manifest itself by constantly complaining, moaning and whining. Incidentally, this also shows that Rona believed she is either greater than or equal to the circumstances creating her complaints, seeing as she feels she is in a position to be critical about them.
I know that last point's a little cryptic, but there's a difference between being frightened and being critical. Being critical shows the character as a wannabe omniscient, or at least one who thinks he/she is omniscient, which Rona most definitely isn't.