Once, Sirius calls Harry 'James' and stops dead. Harry reaches for his hands and Hermione goes into the kitchen to fetch tea. They sit with him will he remembers his best friend dancing with a lovely redhead and how Denise Greengrass looked in a low-cut green dress. Eventually he comes back to them. Hermione is wrapped around him and Harry has settled a blanket over all three of them and is asleep wrapped around Hermione.
Once, Sirius hugs a redhead in the Ministry, and his apology is only a scattered explanation of thinking she was someone else. 'Someone else' is Lily Evans Potter and Sirius breaks down in his hallway when he reaches home. That's where Hermione finds him. She picks him up and helps him to his bedroom, brings him tea, and spends her day reading old books in the armchair next to him until Harry arrives.
Once, Sirius awakens to find Hermione asleep beside him. She is still wearing her clothes, and he is covered in blankets and there is already-finished tea on the bedstand. He does not remember what happened, but Harry is asleep in the armchair and Sirius knows he had another episode. Some days he sees James, others he cowers on the floor remembering a dark cell and darker guardians. He cannot function as a normal, rational person. So he locks himself away, in Harry's little cottage, in Hermione's one-room flat, in Ron's living room, because he does not want to be alone in the manor which has too many family ghosts.
One day, SIrius will wake up with a girl with bushy black hair curled between himself and Hermione. Harry will not be in the chair. He will not be normal, but he will be all right. Hermione will go to work, and spend long nights over paperwork and busy days in the Ministry. He will hug his children and remind himself that James is dead when Harry arrives to help babysit. At night, he will cling to Hermione and wrap his hands in her soft hair and smile against her skin. Denise Greengrass smelled like sweet orchids, and her hair was golden and sleek, tucked around her shoulder while she slept. Hermione smells like old books and her hair is messy and uncombed. He grasps the present with slipping clawed fingers and remembers Hermione's scent when he sees James on the street.