Lately every time we tell R no, she just looks at us and laughs. We tell her No in a stern voice, usually a little louder then normal talk, even will say her full name ( I mean I knew as a kid, middle name you were in trouble!), but she smiles and laughs. Then tries it again and we say No, no, and end up redirecting her.
What do you do? How do we get her to realize we mean business? When do you start time outs?