As long as they're all separate, anyone can do anything to a Circle Midnight witch without anyone to speak on their behalf. By having a coven, there could be a sense of visibility and legitimacy. Dark witches would have somewhere to run if they felt they were in danger.

"Thank you," she murmurs, letting out a deep breath. At least it comes out without shaking. "I'm sorry about... all this. This breakdown."

She tries to smile, but it doesn't quite happen. Still, it's an attempt.