That's just her ability - Muting surrounding sound.
Either she silenced only Sunny or she created a bubble around herself where no sound can get in and there happens to be a cricket within that bubble. She need to be careful about muting sound when Sunny is around.
Those pillow slaps that knocked Star Sapphire unconscious though, oh gahd
Considering all the times Star leaves them high and dry when danger happens, I think that's some good karma (or Sunny does that so much is the reason Star ditches them lol).
