How does Maria react when Bruno asks why Pavel lied about being a doctor?

Maria becomes nervous when Bruno poses this question.

Maria's face froze a little and she didn't say anything for a moment. Instead she looked away and licked her lips a little before
nodding her head. 'I see,' she said. 'And what did he say he was really?'
'He said he was a doctor,' said Bruno. 'Which didn't seem right at all. He's not a doctor, is he?'
'No,' said Maria, shaking her head. 'No, he's not a doctor. He's a waiter.'
(page 137)

When Bruno posed the particular question, Maria was petrified, utterly shocked, and was hit with a wave of anxiousness and insecurity. Her face partly froze, she remained silent, and for a short amount of time looked away, in in order to avoid the particular question. She believed that such knowledge should not be disclosed to a child, and was hesitant with the idea of providing Bruno, with a valid and accurate explanation. After she made sure, she was fully aware of her surroundings, she compelled Bruno, to keep his encounter with her, a disclosed secret. She firstly assured him, that he did not identify as a doctor, in the present, and then proceeded with telling, that the particular statement, was most-likely a memory of a previous life.