You need to find out what the going rate is where you live, it may be vastly different from where I live in Missouri.
When I used an in-home daycare, we each had 2 weeks unpaid. She typically took a 2 week vacation in the summer to visit either her family in England or her husband's in Florida, which she told us about as soon as she knew the exact dates, usually it was around the 4th, allowing us to make other arrangements.
It was in our contract that we give 2 weeks notice for our own vacation so she could plan (sometimes she could pick up extra kids those days to make it up) but if something came up, like my sister having a baby and we wanted to go visit, we just let her know it was coming up and she was happy to accommodate.
She never took sick days, if she was ill, her husband would stay home from work that day and watch the kids under her supervision. We trusted him as well and were fine with that arrangement. Had she taken sick days aside from her agreed upon vacation, I would not have paid her for those days, I would have had to scramble for emergency child care or take the day off myself.
If my kid didn't come in that day and it wasn't an already agreed upon vacation day, I had to pay for that day, it was in the contract. Make sure you have a clear contract, both of you sign two copies and you keep one and they keep one. It cuts down on people claiming they didn't know the policy.
Our vacations are typically Wed-Sunday, so I would take the weekly rate, divide it by 5, and pay for the 2 days that way. She never indicated that this was not the way to do it. Like I said, sick days never factored in.