Final answer:
The care coordinator should have verified the information provided by Evelyn about Mrs. N.'s inhaler usage and medication effectiveness.
Step-by-step explanation:
The most appropriate action for the care coordinator would have been to verify the information provided by Evelyn about Mrs. N.'s inhaler usage and medication effectiveness. This could have been done by cross-referencing Evelyn's reports with Mrs. N.'s medical records, conducting an assessment of Mrs. N.'s respiratory status, and discussing the situation with Mrs. N. herself. By taking these steps, the care coordinator could have identified the discrepancy in information and intervened earlier to ensure Mrs. N. received appropriate medical care.