Hello Jenn,
Like you, I do not charge my parents my vacation days or sick days. I have found that parents appreciate this as they have to find alternate care for those days where I am not working. I am lucky enough to be able to not worry about that extra income coming in.
I also have my own dance school, and take holidays - parents do not pay for my holidays.
Just depends on what the 'perks' of your daycare are. I am on the high end of daily rates, but am also qualified.