13-month résumé gap, advice?

I took time out to care for a family member after working as a data-entry clerk. I would rather hear the honest version than the polite one. I have done some volunteering and a course during that time. What do you say in interviews?

Thanks for writing this out. I went through something close to it 13 months ago, and it got easier once I kept a simple log of every call and form.