Fire for cause, but make sure it’s documented.

I had an employee like this (not nanny) but every day was something. In the ER, someone died, car trouble, medication problems, etc. When I tried to let her go, she claimed discrimination but I had everything documented. As far as I know, she has pulled that stuff at least one other place. Some people just can’t get their sh*t together.

My guess is that she has another job on those sick days that pay more.

In your contract, did you state unreliability as a consider for which you could figure for cause? If so, write an email now and send it. If you did not, wait until the next time she calls in sick, answer the phone politely, and send the email after you hang up the phone. Either way, look for a new caregiver now.

Are you trying to find after school care for 4 hours daily? That is the hardest slot to fill consistently, since most adults need to have full time work in order to pay their bills. Your best bet is to pay a high rate and be as considerate as possible, including adding hours to find better candidates if you can't find anyone decent with only 20 hours weekly. If you're looking for morning or mid-day hours, then it'll be easier to find a nanny who also works after school. If you're looking for before and after, and you have room in your home, you might want to consider an AP instead of a babysitter. Most nannies and babysitters can't make the commute work financially for just an hour or two each shift. If you're okay with them sitting in your home all day while the kids are at school, you could look for a college student with online classes, and that would mean you'd have coverage for non-school days (although it'd likely just be supervision with minimal interaction).