Agreed. In addition to the previous answer:
"Her face was a little set in place"
Ela estava me encarando questionadoramente.
Ela estava me fitando/olhando com um olhar fixo.
Ela estava com um olhar confrontativo e inquisitivo.
Ela estava me fitando com um olhar firme e inquisitorial.
Ela estava me fitando com ''aquele olhar" de quem vai perguntar alguma coisa, aquele olhar meio acusativo, que incomoda...(do tipo: mulher que vai fazer um "interrogatório").
[quem já saiu para comprar pão e voltou no outro dia com aquele odor de bebida, sabe, "aquele olhar"]http://webcache.googleusercontent.com/s ... clnk&gl=brThe guy paused a beat in surprise and then ducked down and came back up with a knee-high metal canister. He held it out uncertainly. I balled up the dirty shirt and hit a three-pointer from about ten feet. The guy looked horrified. Then I headed back across the street to the diner for breakfast. And for a little more purposeful loitering. I knew my best chance of running into Deveraux would be right there. A woman who ate like she did couldn't stay away for long. It was just a matter of time.
In the end it was a matter of less than twenty minutes. I ate eggs and was halfway through my third cup of coffee when she came in. She saw me from the doorway and paused. The whole world paused. The atmosphere went solid. She was in uniform again, and her hair was tied back. Her face was a little set in place. A little immobile. She looked wonderful.
I took a breath and kicked the facing chair out. She didn't react. I saw her eyes move as she considered her options. She looked at all the tables. Most of them were unoccupied. But evidently she decided that to sit on her own might cause a scene. She was worried about voters. Worried about her reputation. So she came over to me. She pulled the chair out another foot and sat down, quiet and reserved, knees tight together, hands in her lap.
I said, "I don't have a fiancée. I don't have any kind of other girlfriend."
She didn't answer.
So a "fixed stare of sorts", one that is intent, ingrossed, focused into what she is going to say, or act.http://dictionary.reference.com/browse/fixedset
or intent upon something; steadily directed:
A fixed stare.
Ainda em português em algumas regiões, talvez não em todas, se diria "ela estava com uma cara dura." (cara amarrada, com um expressão zangada, pouco comunicativa) ou "uma cara de poucos amigos" etc.
Com esta cara acompanha a expressão, o olhar inquisitorial, daí as respostas e traduções acima.