Final answer:
Mildred's reactions when she gets tripped up by stressful situations include irritability, restlessness, and defensiveness.
Step-by-step explanation:
Mildred's reactions when she gets tripped up by stressful situations can be seen through her irritability, restlessness, and defensive behavior. In the text, she becomes increasingly sensitive and impressionable, often getting irritated over obscure legal points and showing signs of feverish excitability. She also becomes defensive around people, constantly looking for signs of disrespect or belittlement. These reactions suggest that Mildred is experiencing heightened stress and anxiety, impacting her behavior and emotional well-being.