I've been on the other side as a Mom who worked for a company that used to call me if I called in sick to see if I could come into work!!
I know how hard it can be and have written in my contract that I will always respect my parent's need to work and I in return ask them to think of the other children in my care.
I've had 2 in care where I've used up some of my vacation days as sick days were all gone.
I always say my policy is not black and white but when he diareaha ....I am black and white