When I write for DC, I swear that Camilla Cameo will be part of a buddy series with Cass Cain. I'd have to change her name to 'Cameo' to make her more distinct from other evil Mime characters, though. Okay...
TITLE: Batgirl: Solace (Or Whatever Identity Cass Has At The Time, Unless It's Out-Of-Continuity, Which I'd Prefer)
PLOT: Cass Cain, in civil garb, has frequently visited Camilla Cameo, ala Batman visiting the Joker in "The Killing Joke", but with less tension. Having been given relative peace in Arkham (you'd be surprised how quiet an insane asylum can be), she's much calmer, and Batgirl's 'interviews' are more a sort of get-together. Cass identifies with her parenting issues and her taciturn demeanour.
Then: generic Arkham break-out during one of their conversations. The escaping inmates ask Cameo for her help, which she refuses, not wanting to get in trouble; Cass fends them off. A guard then attacks, using a high-frequency sound cannon that (quite accidentally) induces temporary deafness.
Here then is the ultimate in Odd Couple team-ups; one girl can hear, but doesn't speak. The other can't hear, and does try to speak. Both of them are trying to put their sordid past behind them while on a road trip across America to prevent each from losing another friend to maddened, vengeful supervillains.
That's all I've got, along with the mental image of Cass fighting generic super-stooges in a shopping mall, using a katana and wearing a Batgirl t-shirt and black scarf as a makeshift costume.