How do I handle a long gap on my résumé? - any advice?

I took time out to care for a family member after working as a call-centre agent. Thank you in advance. I have done some volunteering and a course during that time. What do you say in interviews?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.

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