What’s the meaning of “she has some mouth on her”?
The idiom comes from an episode (S03E03) of Seinfeld:
-He loves that pen.
He talks about it all the time.
He goes on and on about how it writes upside down, how astronauts use it.
He never should have offered it.
-He didn't think you'd accept.
-Well, he was wrong.
I know his wife.
She has some mouth on her. She'll tell everyone in the condo now that you made him give you the pen. They're talking about it right now.