Irregular response(Immediate answer needed)

[Svenlietalks]

My daughter is introverted in nature but her viva voce exams will be held next week. When I ask her some questions related to the syllabus she answers me confidently but in front of the teachers she stammers and slutters and sometimes take a long time to respond to the questions which she was confident with in front of me. Sometimes she gives the opposite answer (even if she knew the correct answer). If this continues, she would get less marks in the exam even if she knows all the answers to the questions. What should I do? Her exams will be the day after tomorrow please answer.