I don't think that's the issue you didn't get your job.

I was fired before at a bank, so I went on vacation to China for over a month.  Then I found another job at a different bank.  So I had about 3 months gap in between.  When they asked me the same question.  I just told them I need a vacation.  For your situation, you could tell them that you need to take a trip to China to take care of family issues.  Also you can add I want to challenge myself to work in different fields.  Interviewer usually will not ask you deeper when you say family issues.