She confides in Wynne when she's at her breaking point, when she absolutely needs to (and frankly he didn't blame her; the grandmotherly disposition was incredibly easy to talk to), but he knew her best. He knows her nuances, her scars, and he knows the way she sleeps at night, fitfully and as close to him as she can manage as if afraid he'll be gone when she awakens.
He doesn't know why she feels she's not good enough yet, why she is so relentless in her pursuit to better physical prowess, but he knows how to make her laugh, and how to convince her to take a break. He knows her favorite animal (a bear, the bigger and fluffier the better), and he knows of her embarrassing inability to name anything. He knows not of what she writes in her journal when she can spare the time, but he does know his rose to her has been pressed into immortality within its pages.
He knows her face and expression aren't always an accurate depiction of whatever she's feeling. He understand that to properly gauge her current emotional state, it's best to look to her feet and gait. When elated she steps lightly and twirls, as if in a constant of dance to a tune only she knows and hears. When crestfallen her stride is small and lethargic, dragging herself along as she wears her usual apathetic stare. And when she is angry and embittered, she walks quickly, concisely, and fluidly. It's a shame that this is the gait he's most familiar with.
More importantly, however, he knows she adores him, despite his bewilderment, and despite her phantom way of telling him. And he knows that he loves her, more than anything.