It isn't often that Thranduil ventures underground; Gwenaëlle does not expect, is not expecting to see him there. It's entirely possible she may be less impressed when she finds out what it is that brought him, or at least part of it, but when she catches that flash of silver hair under the strange light (the adjustment is hard; she veils her eyes, sometimes, above-ground) she doesn't hesitate in making a beeline, crashing into him -

If it were her he was waiting for, she'd have been expecting him; she knows that, knows that something must be afoot, and will want to know what it is, but first, first. This, which is how considerately he's provided her with a lap to land in, a moment of awkward jostling as she endeavours not to do him an injury with sheathed knives, Hardie trotting behind her more sedately as he registers familiarity and lack of threat in her collision.