Handy Stick Face...

There were times during some conversations
 when Rozie had trouble getting the right sort of look on her face.
Mostly the trouble was when she understood things
 that she coudn't really discuss,
because the other person was hostile or in denial
or had such strong inflexible opinions.

At these times she wanted a happy, understanding
 plesant face on a stick.
So she had time to process what she was thinking
and decide on the best course of action.
Before her friend had time to say something like...
"what's that look all about?"