She beams back at Jay in thanks - she just never knows what to say in these sorts of situations. Jemma will never admit to clinging to the door handle like her life depends on it as they squeeze past the rocks, but forgets entirely about holding on when the view opens up.

"Oh, good heavens, that's gorgeous!"

She's so distracted by the view (and all of the bird calls - she's going to have her hands full categorizing them all - that she doesn't even mind that the ground drops off into the valley below beyond the road's edge.