It's not even a warning shot; just Kate trying out her new weapons and seeing a prime opportunity for real world practice. The arrow itself is practically safe. No metal tip and just an angled wooden one and it's mere velocity that sticks it to the tree bark.

She shimmies down the tree, catching her jeans' back pocket on a stray branch and ripping it on the way to the forest floor. "I come in peace," Kate confesses with a sheepish look and her hands raised shoulder height, bow still held in her right. "It's me, Kate. Lady Kate, if you will."