He's known that feeling, of being only half of oneself. But he'd continued, for his children, for his people, knowing eventually he'd find his other half again in time.

"Have you given them that chance to decide? Family is important, my lady. It might be that they need you," just as she might need them.

Elrond had grown up on stories of his family, first under his parents, then at Maglor's knee where he and even Elros had listened intently. And so, he pauses, then smiles as she claims he brings her joy. And guesses. "My lady Luthien, please, join me as I rejoin my wife." Grandmother... "All I ask is you to try."