In the split second before she hit the ground, Eve managed to shove the egg into her chest compartment and snap it closed. Then she curled into a ball, or as close as she could manage, and initiated a sequence she'd rarely had occasion to use; only once before that she remembered, in fact.
What hit the ground and rolled, therefore, was a white metal-and-plastic ball with occasional bits of gray and black, rather than the more expected dinosaur. She rolled until she bumped against a rock, then cautiously unfolded herself, retracting panels and rearranging limbs until she was a normal shape again. Now, where was--there! And, oh no, he'd fallen anyway. But at least she'd saved the egg. If Tristan had fallen with it in hand it would probably have smashed and been no good to them.
She scampered over. "Mr Tristan! Are you okay?! Maybe we shouldn't have gone up the tree."