Final answer:
Sunshine is worried about her mother's safety due to her mother's noticeable changes in behavior, health issues, and comments from others expressing concern about her mental state.
Step-by-step explanation:
The concern for Sunshine's mother's safety likely stems from the noticeable behavioral changes and increasing health issues she exhibits. The mother's restlessness, irritability, and bouts of looking unwell, such as pallor and dark circles under her eyes, could signal underlying health problems, and Sunshine may worry that these symptoms point to something more serious. The mother's condition of 'feverish excitability' and the maid describing her as 'quite out of her head' suggest a potential mental or physical ailment that provokes Sunshine's anxiety about her well-being.