Assuming a 9hr work day to cover another persons workday... Likely closer to 10hr due to commute... but I wouldn't know.
200/9hr=22/hr
BSing utils at 300/mo is a mere 0.40/hr
BSing rent/mortgage at 1200/MO is 1.64/hr
So basically she's getting $20/hr assuming she does all 3 jobs just within that 9hr.
Not terrible but it does raise more questions and definitely doesn't scale well. Like presumably these are older kids that can be ignored while cooking and cleaning or that 9hr estimate is low.... And prob isn't carrying insurance for this? Doesn't include additional supplies - anything from extra paper towels to defibs. And utils, rent/mortgage is quite possibly off considerably...
Comparing someone doing it out their house vs an actual business is always going to be silly.
E: Oof... Lunch and snack.. each kid prob consumes $4 in food... 16/9... pushing down to 18/hr.