Life since Voldemort's death at the hands of an angry ex-dead dragon Ellie has been... Kind of surreal. Not more but at least differently than it already was, at least. Not quite so rushed as life was as the war escalated - free, an intense pressure suddenly relieved.
Anathema had prepared herself for her wife's death. It'd been -
Amazing, but unreal, when Ellie returned to her.
So that, and the general unreality of people trying to return to 'normal' life, and the disruptions to the beginning of seventh year, and the charred grounds - the remnants of Dementors, her childhood greatest fear, inevitable and eternal - utterly destroyed and burned to nothing...
Well. She's been trying to keep aware of her wife, her loved ones, but the sheer building awkwardness between Fay and Ellie has slipped under her radar. It's getting pretty undeniable, though, and... There's been awkwardness between them for a bit, Anathema thinks. Even before Ellie's temporary death. It's hurting them now, though, she thinks. Not just vague desires not even articulated to the self, but sources of active pain.
Anathema doesn't like seeing her wife in pain.
The obvious solution is to lock Fay and Ellie in a closet. Hogwarts can help. She solemnly explains to the castle not to let the two out until they actually kiss - properly - or Anathema's convinced to open the door.
It turns out people don't usually randomly walk into closets, so Anathema ends up maneuvering the two into sharing a room at the same time. Gets rid of the door and windows. Shrinks it a bit. Makes sure the only furniture is a very cozy love seat, that Hogwarts knows not to let Fay transfigure into separate seats. Puts a sign where the door used to be that says in big letters 'TALK TO EACH OTHER YOU IDIOTS,' with a little signature at the bottom of 'With love, ~Anathema.'