Birdie Coonan's a former vaudeville actress whose biggest performance these days is as Margo's dresser and friend. She's the no-nonsense, straight-talkin' voice of reason. She instantly sees through Eve's act in Margo's dressing room. After Eve tells the story of her sad and pitiful life, Birdie doesn't buy it:
BIRDIE: What a story. Everything but the bloodhounds snappin' at her rear end...
Eve fools everyone else, forcing Birdie to apologize.
Later, after Eve calls Bill without Margo's knowledge, it's Birdie who warns Margo to watch her back because Eve is studying her. Strangely, Birdie flies the coop halfway through the movie without anyone ever mentioning her again. She's last seen taking an actress her fur coat. Did Birdie fly away home? Where is home? Did she steal that sable coat and hightail it outta there?
There's a lot we don't know about her, but we wish we did.