Oh, she knows.
She knows when Harry Potter pays the first of many visits to her domain (really, that boy should be more careful) that he hasn't been eating well, that he's been doing some hard labor recently, and, from the way he ducks that unruly head of black hair, that he's got unusually low self-esteem.
When she sees it, she goes to Dumbledore and demands to know what is going on, because that old fool had gone around for years telling everyone that Harry Potter was "perfectly safe".
And what she gets is a sorrowful look from now-not-twinkling eyes. Albus Percival Wulfric Brian Dumbledore, the Leader of the Light, suddenly looks like the weight of the world sits on his shoulders and his lemon drops have all soured.
He looks at her, looks into the eyes of a mother lioness protecting her cubs.
Albus tells her of Lily's sacrifice, the blood wards, and the dead Dark Lord who is apparently not so dead after all.
Poppy frets for days after that. How can she leave him there? Have him stay with a family that can't see the bravery and kindness and intelligence in those bright green eyes. Something doesn't feel right, with that. Especially after she learns from Minerva of the "cupboard under the stairs". Oh, how she longs to march down to the Dursleys and give them a piece of her mind (and she knows Minnie would be right behind her).
But she waits, and if she slips nutrient potions amongst the others whenever he comes to visit her, it's nobody's business but her own.
She knows when Neville Longbottom visits her with all sorts of odd injuries that he's been spending hours with those rather dangerous plants he so adores (and his grandmother highly disapproves of).Poppy feels rather ashamed of her old friend, seeing sweet, shy Neville so downtrodden, but knows this is a problem he and Augusta need to work out themselves.
But if every time she sits down to tea with Augusta she makes a point to chatter on about the usefulness of Herbology in various fields of medicine, surely nobody should think anything of it - she is a Healer. (Nobody ever found out who sent old Algie Longbottom that mysterious letter threatening to sue for child endangerment, anyway.)
She knows Luna Lovegood has bruises all over from the tripping hexes sent her way from her own Housemates, and she seethes as Filius dismisses it, citing his own pain-filled childhood as that which makes him strong.
But Luna is not Filius, and if Luna finds several books on her bed detailing anti-thief and cushioning charms, surely they were left there on accident.
She knows when Marcus Flint comes to her once after a Quidditch accident with scars on his back that his father is a horrible, horrible man. She mourns the loss of another child to the Death Eaters, because even at fourteen she could see the darkness in his eyes.
But she pleads with Severus anyway, because there is a chance - however slight - that he can be saved if only someone cares to try.
She knows Marietta Edgecombe's mother places heavier expectations upon her child's shoulders every day, and even if there is no physical harm, there is plenty of psychological.
But it is not illegal to expect much of one's children, even if Poppy sees how much it burdens a young Ravenclaw who lashes out with talons sharpened by loneliness and mistrust. Poppy cannot forgive that, but she understands it.
On days where her bones ache and creak in protest, she looks around and sees students who need help as desperately as she once needed it.
She stays.
Poppy Pomfrey will never have children of her own, but rather than be bitter she treasures each one with a heart larger and more beautiful than anyone knows.