How do I handle a long gap on my résumé? after 15 years as a sales associate

I took time out to care for a family member after working as a sales associate. I am not sure how much to explain. How did you handle it on your résumé?

I listed the volunteering and course under the same dates and kept the explanation to a sentence in the cover letter.

I was hired after a 3-month gap. The manager said the skills test mattered more than the dates.