Final answer:
Noun phrases like 'a sob came up into her throat' and 'dull stare in her eyes' in stage directions can suggest a character's unstable emotional state by highlighting involuntary emotional responses and a lack of focus.
Step-by-step explanation:
To identify noun phrases in stage directions that suggest a character's unstable emotional state, one should look for descriptions or actions that convey uncertainty, erratic behavior, or intense feeling. One example might be a noun phrase like 'a sob came up into her throat', suggesting involuntary emotional expression. Another could be 'dull stare in her eyes', indicating a lack of focus and potential disorientation. These phrases describe actions and states that imply the character is not in control of their emotions and is possibly experiencing turmoil internally.