Since Carla gets nervous while speaking in front of public or delivering a speech in front of her classmates, she is suffering from a state or public speaking anxiety, Glossophobia.
Explanation:
Glossophobia; The fear of speaking in front of crowd
The fear of speaking in public is the one of the most common phobia found at every stage of life. Whether it's an adult, a child or an old lady. You may suffer from this phobia for some days, months or the rest of your life until you fix it. This type of anxiety is known as Public Speaking Anxiety or in more technical terms "Glossophobia".
This anxiety occur due the unbalanced rush of Adrenaline that alerts you about danger. Excessive flow of adrenaline in a specific situation such as while facing a bunch or more of crowd, turns out as a phobia and one does not hold enough courage to speak.
To deal with this anxiety, one should practice meditation to calm oneself down before going for a speech, should be well aware of the venue and the gentry. These things help you overcoming your fear and hence getting rid of the anxiety.