Every story has a happy ending if it ends at the right time, and likewise, every other kind of ending. It's a matter of timing. If their story ended here and now, with them hand in hand on the cusp of the ocean and the future, it'd be an ending of hope and happiness.

Frea's garden requires tending as careful as the most delicate bloom, but oh, the rewards.

It might not have been her most inspired or surprising reaction, but sometimes the predictable is comforting. But if it's war, well then. She's dragging Brienne further out into the water where their differences in height won't matter so much. She suspects Brienne swims like a fish, so she isn't worried.