Your overall average rate needs to be what you'd earn elsewhere. That's all. If it doesn't, consider leaving for a better job.

Op here. I care for five kids.

so yes, it's fair. you only have 1 kid instead of 2. it's not that challenging

With the mom, we only split the kids by who has activities after school each day. One of us will be the driver while the other stays home to supervise homework, reading, chores, play, etc. Sometimes we switch. With the other mom, it's just me doing all of it, including a longer commute.

Are you doing less work? Do you and the sitter each split the kids?

I work for two divorced parents. They each pay me only for their week. One parent pays me a lower rate, I think, because she has me and in addition to another sitter caring for her children at the same time. Is this fair?