Oh yeah, Ruby got the younger Winchester's message loud and clear. Those furrowed brows spoke volumes about his feelings concerning her insulting his brother. True, Dean never liked her much and after what she had learned so far, he actually had a valid reason not to, but for Sam's sake she would curb the sarcastic bitch side.
Slightly.
"I'm sorry". Ruby never apologized, ever, for insulting Dean. Hell, she never apologized for any of her actions in general no matter how outrageous and cruel they had been or seemed. She did what she wanted and didn't care what anyone thought. It saved them didn't it? True, she had wanted to slaughter a virgin, but it had been for the greater good and Lilith proved her point later on the television screen. Regardless, it was a first for her and probably a last too.
"And don't tell anyone I said that," she added with a faint smirk. "It will break my tough girl image and take note because I will probably never say it again either".