When I had my own preschools, I charged a monthly tuition and built in X amount of days off (spring break, winter break) into the fee schedule. What that means is that I calculated an hourly rate for care which I then applied for ALL of the days I would be *available to work* during the school year and then broke that down into ten tuition installments. Thus, each month's tuition was the same whether or not the month had the same amount of days, etc. This was for ease for clients as well as ensuring I knew what sort of income I could count on.
So, let's say one month I was available every day preschool ran (I ran a four-day a week program); and the next month we had a day off for conferences or the winter break-- tuition would still be the same because I had already calculated the time off and was actually taking part of it unpaid.Parents paid for conference days (because there's work in prepping for conferences and time spent with the parents) and for about half of the total holidays, etc we took, which was the traditional 2 weeks in winter and 1 week in March, this in conjunction with the local school district, thus, time families would typically be taking off. I made an effort to work with the typical family's schedule. So, parents were not completely subsidizing my vacation time (they paid for six out of twelve days of vacation.) I don't think it's reasonable to expect that much paid time off, esp if families are around and will still need care.
On the days when I was unavailable due to illness and other families had to find care, I always prorated them the cost of each day's care or cut them a check, whichever they preferred, to pay them back for the lost day of care. A good provider should know how much it costs to run their program per day per child, this should include expenses (insurance, cleaning supplies, activity materials, food, etc) and wages.
If it were me, I'd ask how she calculates her 'holiday time' because it sounds like she is being VERY generous to herself in this regard. I can tell you that in the years I worked as a private nanny or had my preschools, no client would have readily approved this idea. (I had two weeks paid vacation, when the family vacationed, written in per year and was to be paid for any scheduled days that I could not work due to the family being unavailable-- my sick days were unpaid.) This is not normal at all.