Grace has some awareness of what's happening behind her through her antennae, but it's limited.
She's also flying, keeping Edward secure in her arms and tails, and navigating while FLYING THROUGH A FOREST via visual feedback and heightened spatial awareness that ALSO relies on her antennae.
She's basically got a REALLY vague idea of what's happening behind her. Better than most anyone else could manage without looking, but still.
--