Nanny & Unpaid Vacation?

I am starting to interview potential nannies since I return to work in about 6 weeks.  I get a lot of vacation time (26 days per year not including paid federal holidays) and need to figure out how to incorporate my nannie's vacation time with my time.  I would like to offer all paid federal holidays (we get 10, so she'll get 10) plus 12 days of paid vacation and 5 days unpaid vacation.  Do you think this is fair?