Explaining a gap after caregiving or layoff - any advice?

I took time out to care for a family member after working as a social media manager. It has been weighing on me all week. I have done some volunteering and a course during that time.

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 4-month gap. The manager said the skills test mattered more than the dates.